By Ozcan Yildirim

BUDAPEST, Hungary

The Saudi Consulate in Istanbul should prove whether or not missing journalist Jamal Khashoggi exited the building after entering last Tuesday, Turkey's president said on Monday.

"It is our humanitarian and political duty to closely follow the issue," Recep Tayyip Erdogan said in Budapest during a joint press conference with Hungarian Prime Minister Victor Orban.

"There are some people that came from Saudi Arabia [that day]. The public prosecutor's office is looking into the issue," he said, adding that footage from airports is being studied.

Addressing the Saudi version of events, Erdogan said: "The Saudi Consulate officials in Istanbul can't get away with [simply] saying 'he left the building.’ The claimants are obligated to prove their claims. If he left the building, then you need to prove it."

Khashoggi, journalist and columnist for The Washington Post, has been missing since he entered the consulate in Istanbul on Oct. 2.

Turkish police investigating the case said Saturday that 15 Saudis, including several officials, arrived in Istanbul on two planes and entered the consulate while Khashoggi was inside.

Istanbul prosecutors are investigating the incident, while the consulate said on Twitter that it was working in coordination with Turkish authorities.

Turkey on Monday said it expects "full cooperation" from Saudi authorities in finding the missing journalist.

EU membership process

On Turkey’s EU membership process, Erdogan called for sincerity, stating that it needs to be clear whether or not the EU will accept Turkey.

"Turkey has been stalled since 1963. No EU member state was treated in such a way," he added.

In 1963 the Ankara Agreement between Turkey and the European Economic Community -- a predecessor to the EU -- established an association between Turkey and the bloc.

Turkey applied for membership in the EEC in 1987, and it became eligible for EU membership in 1997. Accession talks began in 2005. 

But talks stalled in 2007 due to objections from the Greek Cypriot administration on the divided island of Cyprus, as well as opposition from Germany and France.

On the refugee situation in Turkey, Erdogan said that there are currently nearly 3.5 million Syrians in Turkey, while some 250,000 have returned to Jarabulus, Afrin, and Al-Bab -- areas liberated from terrorists in a Turkish-led operation -- and more than 60,000 to Idlib.

Hungary's security 'directly related to Turkey'

For his part, Orban said that Hungary’s security is “directly related to Turkey.”

“A stable government leading in Turkey is also a guarantor of Hungary’s security,” he said.

Stating that Turkey, like Hungary, lies along migration routes, Orban said that it is important for Hungary that Turkey is stable to establish peace in the region and deter irregular migration.

Stressing the importance of the 2016 EU-Turkey migrant deal for the security of the European continent, Orban said that Hungary must also show its alliance with Turkey.

In March 2016, EU and Turkey reached an agreement to stop irregular migration through the Aegean Sea and improve the conditions of more than 3 million Syrians in Turkey. 

The EU pledged €6 billion ($7.44 billion) in funding for the refugees, including a €3 billion ($3.72 billion) tranche by the end of 2018. Turkey hosts some 3.5 million Syrians, more than any other country in the world.

While spending around $25 billion helping and sheltering refugees since the beginning of the Syrian civil war, Ankara has complained of the EU dragging its feet in providing the funds it promised.

“We have to congratulate Turkey for opening its doors to millions of refugees,” said Orban.