Timeline of Iran's nuclear program

ANKARA

Six world powers and Iran reached a final comprehensive nuclear agreement on Tuesday after negotiations lasting 22 months on Iran’s controversial nuclear program.

Although there are some disagreements between Iran and the P5+1 group over the time and scope of removing sanctions and inspectors' access to Iran's military facilities, the way seems clear for Iran to emerge from nearly a decade of international isolation

Below is a chronology of milestones in Iran’s nuclear program, which overwhelmingly occupied Iran’s international agenda over the last decade.

1957: Iranian Shah, Mohammad Reza Pahlavi, signs a nuclear cooperation agreement with the United States, part of the U.S. Atoms for Peace program.

1967: Tehran Research Reactor -- first of its kind in Iran -- begins operating.

1968: Iran signs the Nuclear Non-Proliferation Treaty.

1973: The U.S., France, Namibia, South Africa and West Germany sign agreements on nuclear matters.

1974: A West German company begins the construction of the first nuclear plant near Iran’s southeastern city of Bushehr. Shah Pahlavi says Iran would have its own nuclear weapon, but steps back in later conversations.

1979: After the Islamic Revolution, the new Iranian administration cancels agreement on building a new power plant. An agreement signed with the U.S. a year earlier on providing enriched uranium is cancelled. Many nuclear experts leave Iran, after religious leader Ayatollah Ruhollah Khomeini disbands the nuclear program. Iran-U.S. cooperation agreements are cancelled after radical Iranian students take U.S. Embassy workers hostage in Tehran.

1980-1988: The Iran-Iraq War leads Ayatollah Khomeini to decide to once again embark on a nuclear program, which aims to ease restrictions, seeks new ways to agree with the Germans in repairing and completing the Bushehr nuclear plant.

June 4, 1989: Ali Khamenei becomes the country’s new supreme leader, after the death of Khomeini.

1995: Iran agrees with Russia so Moscow completes the research reactor project in Bushehr. The reactor is finally completed in 2010 after disruptions and delays. 

1996: U.S. President Bill Clinton approves embargo on Iran for trying to acquire nuclear weapons.

1999: Iranian President Mohammad Khatami becomes the first Iranian leader to visit Saudi Arabia after the revolution. Khatami and King Fahd express concern about Israel’s nuclear weapons program.

2002: Iran signs new agreement to complete the construction of the reactor in Bushehr.

2003: U.S. invades Iraq to clear the country of alleged weapons of mass destruction and Iran is ordered to re-suspend its nuclear program. Iran’s leader says nuclear weapons are forbidden in Islam. The International Atomic Energy Agency, known as IAEA, says Iran has failed to comply with nuclear Non-Proliferation Treaty (NPT) after the agency finds traces of highly enriched uranium.

2004: Tehran inks the NPT Additional Protocol along with France, Germany and the U.K. and agrees to suspend uranium enrichment activities.

2005: Mahmoud Ahmadinejad is elected President of Iran. Ahmadinejad, despite the threat of sanctions, speeds up the nuclear program and launches the heavy water production plant in Arak.

2006: The UN Security Council imposes sanctions on Iran, blocking the import and export of sensitive nuclear material, equipment, and ballistic missile development.

2008: Negotiations with Western countries are blocked as Iran gives negative response to the demands to halt its uranium enrichment.

2009:

- April 8: The U.S. starts participating along with Russia and China in negotiations with Iran over its nuclear program.

- September 25: American, British and French officials share information about Iran covertly building a secret enrichment plant, which Tehran denies.

- October 1: Iran agrees to hand in to Russia 1,200 kg of enriched uranium to be used for scientific purposes for conversion into fuel rods, only to back out of its decision on November 18.

- November 5: Iran announces it would allow international inspectors to enter newly built nuclear plants.

2010:

- January 10: U.S. President George W. Bush rejects Israel’s request on Washington to support Tel Aviv’s missile strikes on Iran’s nuclear facilities. The media later widely cover a cyber-attack on Iran’s Natanz nuclear facility, claiming Israel and U.S. are responsible.

- February 18: The IAEA announces it has extensive evidence on Iran’s nuclear activities.

- May 17: Iran signs agreement with Turkey and Brazil to send uranium abroad, but the West rejects the 10-point declaration of the three countries. 

- June 9: The UN decides to apply new military, trade and financial sanctions on Iran, forbidding nuclear cooperation with the Tehran government. It further stipulates that it would allow search on the planes and ships of a country that is suspected of cooperating with Iran.

October 29: Iranian scientist Majid Shahriari is killed and scientist Fereydoon Abbasi -- listed for UN sanctions -- is injured in two separate, yet similar bomb attacks. The Iranian government blames the United States and Israel.

2011:

- June 8: Iran and the P5+1 hold nuclear talks in Istanbul, but with no progress.

- May 10: Bushehr nuclear power plant begins operating.

- May 24: The IAEA announces that an increase is spotted in uranium enrichment activity in Iran.

- November 8: The IEAE releases report saying Iran is conducting a secret uranium enrichment program. Iran denies the allegations, claiming the evidence is forged.

2012:

- March 3: Iranian media report that at least 3,000 new-generation uranium enrichment centrifuges were produced in Natanz nuclear facility.

- May 24: Talks fail in Baghdad between Iran and the P5+1.

- July 1: The EU embargoes Iranian oil. The Iranian government threatens to block ship traffic in the Strait of Hormuz and begin missile tests. The EU expands sanctions on Iran, including financial, metal, natural gas and money transfer curbs.

- July 12: Russian Foreign Minister Sergei Lavrov offers “road map” to implement the P5+1’s proposals. The offer is positively greeted by Iran, but is not accepted due to the length of time it would take to implement it.

- August 30: The IAEA reports that Iran is doing nuclear weapon tests and the number of centrifuges installed at the Fordow enrichment plant increases.

- September 17: Israeli Prime Minister Benjamin Netanyahu says that within the next six months Iran’s enriched uranium capacity would be sufficient to produce a bomb.

2013:

- January 7: Iran's Oil Minister Rustem Qasimi declares that Iran’s oil revenues have dropped by 40 percent as Iranian riyal continues to depreciate.

- February 23: The IAEA announces it has found new uranium deposits in Iran and 16 locations where nuclear plants are to be built. Iran and the P5+1 resume talks in Kazakhstan, but fail to reach any compromises.

- March 14: U.S. President Barack Obama, in an interview for an Israeli network, says it would take more than a year for Iran to make nuclear weapons, contrary to Netanyahu’s statement.

- April 12: Netanyahu says that his country has different sensitivities from the U.S. in regard to Iran’s nuclear program, and that Israel would defend itself.

- May 22: The IAEA reports that Iran’s nuclear program has made great advances but is not yet in a position to cross the red line.

- June 25: Hassan Rouhani is elected President of Iran. Rouhani assigns FM Javad Zarif as negotiator in the nuclear talks.

- August 25: The IAEA reports Iran’s uranium activity has slowed down.

- September 19: Obama sends letter to Rouhani, saying that sanctions could be decreased in exchange for cooperation.

- September 24: Rouhani gives moderate messages in his speech at the UN General Assembly.

- September 27: Obama speaks with Rouhani by phone about the nuclear program, marking the highest level of contact between the two countries’ leaders since the revolution in 1979.

- October 14: Talks between Iran and the P5+1 resume in Geneva. It is announced later that the negotiations would continue in November.

- November 11: Iran announces it would cooperate to resolve the issues stated in the IAEA reports, allow international inspectors to enter nuclear facilities and pledges to permit controlled supervision.

- November 14: Obama asks Congress to support efforts towards a nuclear deal.

- November 24: Iran and the P5+1 agree to extend negotiations and sign a six-month agreement whereby Iran pledges it would freeze nuclear activities, drawing criticism from Israel and Saudi Arabia.

2014:

- January 20: The temporary agreement signed in November comes into force. A part of Iran’s money in foreign currency accounts is allowed to return to the country.

- July 18: The duration of the agreement is extended by another four months.

- August 27: The IAEA says that the Arak heavy water production plant, which was then under construction, is producing less plutonium, but the nuclear agency does not say how much is produced.

- November 24: With the final agreement not yet reached, the temporary agreement is extended for another seven months. The sides announce that the framework over the nuclear program would be reached no later than March 31 and a final agreement will be signed by July 1.

2015: 

- March 3: Israeli Prime Minister speaks at the U.S. Congress, calling on U.S. lawmakers to oppose a prospective deal with Iran. 

- March 8: Obama says if Iran is not willing to provide "transparency and verification" for its nuclear program, the U.S. and P5+1 countries would "walk away" from negotiations. 

- March 9: A group of 47 U.S. Republican senators send an open letter to Iran's leadership, saying that any nuclear deal between Obama and Tehran could be reversed once the U.S. president leaves office.

- March 23: 367 members of the U.S. House of Representatives write a letter to Obama saying any agreement with Iran over its nuclear program has to be approved by U.S. Congress. 

- March 31: Last day for Iran and the P5+1 group to ink a framework deal in Swiss city Lausanne. The sides fail to reach a deal, as negotiations are postponed for a day on two occasions.

- April 2: Iran and the P5+1 countries reach a framework deal. The sides agree to begin drafting the text of a final nuclear agreement and sign it before June 30 deadline.  

- April 20: Iran's Oil Minister Bijan Zangeneh says the Organization of the Petroleum Exporting Countries (OPEC) should make room for Iran's oil production, underlining that his country wants its crude oil export levels to return to pre-sanctions levels. 

- May 5: Iranian Deputy Foreign Minister Abbas Araqchi says all political, economic and financial sanctions on Iran should be lifted the same day a final nuclear agreement is reached.

- May 6: Zangeneh announces that his country intends to raise its oil production and exports once the sanctions are removed. 

- May 13: Iran refuses to give the IAEA access to its military sites, saying the nuclear watchdog is only responsible for technical issues and providing verification of Iran's nuclear program. 

- May 20, 21, 22: Supreme Leader of Iran Ayatollah Ali Khamenei, Iranian President Rouhani and Foreign Minister Javad Zarif say their country will not allow any international inspectors access to Iran's military sites or permit interviews with its nuclear scientists, considering this a breach of its sovereignty, and declaring the issue a "red line" during negotiations.

- May 22: Obama signs a bill into law, which requires any final agreement with Iran to be reviewed by the U.S. Congress before the president can remove sanctions on Iran that were imposed by the Congress.

- June 3: Zangeneh says he wrote a letter to OPEC, asking the cartel to take Iran's post-sanction oil production increase into consideration during its biannual meeting in Vienna on June 5. 

- June 5: OPEC does not change its production quota and maintains oil production at 30 million barrels a day. Zangeneh says Iran does not need OPEC's permission to return to the oil market once sanctions on the country are removed. 

- June 12: Nuclear talks between Iran and P5+1 group are reported to have stalled due to differences over timing and scope of removal of sanctions and the IAEA's access to Iran's military facilities.

- June 15: The Republican U.S. Senator, who is also the chairman of the Senate Foreign Relations Committee, writes an open letter to Obama, advising him to "walk away" from the talks if Iran crosses the remaining red lines in the nuclear negotiations. 

- June 23: Iran's parliament ratifies legislation which says a nuclear deal with the P5+1 countries would only be valid if sanctions on the country were removed fully and immediately. The bill also bans international inspectors' access to Iran's military sites. 

- June 23: The U.S. Senator Lisa Murkowski, who is also the chairwoman of the Senate Committee on Energy and Resources, says in a report that the U.S. should not remove sanctions on Iran, letting the country increase its oil sales until the U.S. lifts its own four-decade old self-imposed ban on exporting crude oil. 

- June 25: The global research and consulting company Wood Mackenzie says 75 percent of Iran's oil reserves are untapped. 

- June 30: The U.S. House of Representatives' Foreign Affairs Committee Chairman Ed Royce urges Obama to walk away from nuclear talks, claiming the U.S. is giving too much concessions to Iran, adding "no deal is better than a bad deal."

- June 30:  Russian Foreign Minister Sergei Lavrov says any final nuclear agreement between Iran and the P5+1 group must be approved by a resolution of United Nations Security Council. 

- June 30: Last day of reaching a final comprehensive agreement between Iran and P5+1 group. Deadline of the talks is extended until July 7. 

- June 30: Obama says he is prepared to end negotiations if Iran fails to live up to preliminary agreement reached in Lausanne, and warns Iran to abide by the terms of the April 2 framework agreement.

- July 2: IAEA Director General Yukiya Amano holds talks with Iranian President Hassan Rouhani about the country's nuclear issues.

- July 4: Amano says the nuclear watchdog may report on the potential military uses of Iran’s nuclear program by the end of 2015.

- July 5: Iran says its new oil contract model, Iran Petroleum Contract, to attract foreign investment and global oil giants, is ready for government approval. 

- July 6: Iran says progress is made to cooperate with the IAEA. Amano says the sides talked about clarifying the possible military dimensions of Iran's nuclear program, and the agency's monitoring and verification measures on Iran. 

- July 7: Last day of reaching a final comprehensive agreement between Iran and P5+1 group, after postponing the June 30 deadline. However, EU foreign policy chief Federica Mogherini says the sides are going to continue the talks beyond the deadline as no final deal is reached. 

- July 7: Russian Foreign Minister Sergei Lavrov says most sanctions on Iran will be removed. Iran's Deputy Foreign Minister Abbas Araqchi announces that annexes to a final deal on sanctions are 95 percent complete while only a few minor issues remain.

- July 9: The U.S. Secretary of State John Kerry says tough issues remain unsolved in the talks, adding the negotiators will not rush, nor be rushed to reach a final deal. 

- July 9: Global energy consulting firm SVB Energy International LLC says in its report that Iran needs $70 billion of investment to reach its oil production capacity target by 2020. 

- July 10: Global credit ratings organization Fitch Ratings says Iran is looking towards at least five years to boost its natural gas production and exports, even if sanctions on the country are removed immediately. 

- July 10: EU extends the suspension of sanctions imposed on Iran until July 13. Iranian Foreign Minister Javad Zarif states outstanding issues could be settled in a couple of days. 

- July 12: The U.S. State Secretary Kerry says negotiations are coming closer to an end. His Iranian counterpart Zarif says there would not be any further extensions to the nuclear talks beyond July 13. Iranian President Rouhani approves a bill ratified by the parliament on June 23. 

- July 13: Iranian Deputy Foreign Minister Araqchi says he cannot promise that the outstanding issues will be settled today or tomorrow night.

-July 14: Iran reached a comprehensive nuclear deal with the world powers P5+1 countries in Vienna.