Rex Tillerson
Rex TillersonReuters

U.S. Secretary of State Rex Tillerson said Monday that he sees progress in getting European support for tough new sanctions against Iran that could prevent a U.S. withdrawal from the Iran nuclear deal, The Associated Press reported.

After meeting with British Prime Minister Theresa May, national security adviser Mark Sedwill and Foreign Secretary Boris Johnson, Tillerson said they had agreed to set up a working group of experts on fixing flaws in the landmark 2015 agreement.

"I think there's a common view among the E3 that there are some areas of the (nuclear deal) or some areas of Iran's behavior that should be addressed," Tillerson told reporters after talks with Johnson. The E3 are Britain, France and Germany, which are all parties to the deal.

Tillerson specifically highlighted concerns about Iran's ballistic missile program, which is not covered by the nuclear deal, and provisions in the agreement that allow Iran to gradually resume advanced nuclear work.

The working group will begin to meet as early as next week to discuss how to address the flaws "through some type of another side agreement perhaps or a mechanism that would address our concerns," he said, according to AP.

President Donald Trump recently decided to extend a waiver on nuclear sanctions that were imposed on Iran. However, he said it would be the last time he will do so and ordered European allies and Congress to work with him to fix “the disastrous flaws” in the 2015 deal or Washington would withdraw.

Trump has repeatedly criticized the Iran deal, one of his predecessor’s Barack Obama’s signature foreign policy achievements, as the worst ever negotiated by the U.S.

However, European countries have failed to see eye to eye with Trump on the nuclear deal and have expressed their support for the deal even as Trump has criticized it.

Last week, Russian Foreign Minister Sergei Lavrov warned that the Iran nuclear deal cannot survive if the United States pulls out the agreement.

"This agreement cannot be implemented if one of the participants unilaterally steps out of it. It will fall apart, there will be no deal then," Lavrov told reporters at the United Nations headquarters in New York.