WASHINGTON 

The U.S. State Department said Wednesday that Iran is withdrawing Hezbollah forces from Syria because of Washington’s pressure campaign against Tehran, including sanctions and military deployments.

"Our campaign is working. The campaign is starving Iran's proxies of the funds they rely on to operate on behalf of the regime," department spokeswoman Morgan Ortagus said in a news conference.

"We will continue to put maximum pressure on the Iranian regime to deny it the means to conduct its destructive foreign policy."

Ortagus cited the New York Times and the Washington Post newspapers that reported American sanctions on Iran have curbed Tehran’s ability to fully fund proxy groups across the Middle East, including Hezbollah.

The Post said the cuts to Hezbollah's funding were severe resulting in fighters receiving salary cuts and many being withdrawn from Syria where they "played an instrumental role in fighting on behalf of President Bashar al-Assad and ensuring his survival."

Washington renewed heightened pressure on Iran in May, ending a waiver for countries to continue buying Iranian oil while sanctions were taken place, with U.S. Secretary of State Mike Pompeo saying the goal is to bring Iranian exports to zero.

Tensions between Iran and the U.S. have mounted steadily since 2017, when U.S. President Donald Trump withdrew Washington from a landmark nuclear agreement between Tehran and the P5+1 group of nations -- the five permanent UN Security Council members, plus Germany).

Since then, the Trump administration has re-imposed sanctions on Iran’s banking and energy sectors, while Iran has threatened to close the strategic Strait of Hormuz to U.S. oil shipments.

Earlier this month, the U.S. sent a carrier strike group, a bomber task force and Patriot missile battery to the Middle East, citing a "credible threat" from Tehran. Trump also confirmed that the U.S. would be sending 1,500 troops to the region.