As President Trump wages a rhetorical battle with North Korea over its nuclear program, his secretary of state says the nuclear deal with Iran will now be placed under review.
In a letter to Congress, Secretary of State Rex Tillerson said that Iran is meeting the terms of the 2015 deal worked out with the Obama administration and five other countries. But Tillerson added that the current administration would evaluate whether the lifting of sanctions that had been placed on Iran "is vital to the national security interests of the United States."
"Iran remains a leading state sponsor of terror through many platforms and methods," Tillerson said in his letter Tuesday.
He gave no indication of how long the review would take or what the likely outcome would be. The State Department must provide an update to Congress every 90 days.
Trump was a harsh critic of the deal as a candidate, and his administration has taken a tough line with Iran over a number of non-nuclear issues.
Iran has continued to test ballistic missiles — which was not part of the nuclear agreement — and Iran has kept up its staunch support of Syrian President Bashar Assad.
However, Tillerson's letter was in line with many other assessments that have found Iran has kept its part of the bargain. Iran was required to give up almost all of its enriched uranium, which can be used to make a nuclear weapon, and is subject to ongoing inspections by the International Atomic Energy Agency.
In return, many sanctions have been lifted, which has allowed Iran to ramp up its oil exports and earn billions of dollars to help its weak economy.
Iran has said many times that if the U.S. imposed additional sanctions, that would violate the nuclear deal and Iran would no longer feel bound by its terms.
The other countries that were part of the deal — Britain, France, Germany, Russia and China, along with the European Union — remain supportive of the pact and would likely object to any re-imposition of American sanctions.
The deal has allowed many Western companies to resume business with Iran, including Boeing, which has signed two major agreements to deliver dozens of planes to Iran.
The U.S. still maintains some sanctions against Iran for separate, non-nuclear issues, with Washington accusing Iran of sponsoring terrorism outside its borders and violating human rights at home.
The Trump administration has taken hard-line positions against both North Korea and Iran over their nuclear programs, though it's not yet clear whether this will lead to punitive measures.
In the latest sign of U.S.-Iranian tensions, U.S. Defense Secretary James Mattis, who was in Saudi Arabia on a tour of the Middle East, on Wednesday accused Iran of sending missiles to rebel Houthi fighters in Yemen.
The U.S. has supported Saudi Arabia in a bombing campaign against the rebels in Yemen's civil war.
In Iran, Defense Minister Brig. Gen. Hossein Dehqan rejected the allegation and said U.S.-made weapons were being used to commit "crimes" in Iraq and Syria.