Iran Nuclear Deal: In Call With Trump, U.K.'s May Stresses 'Strong Commitment' to Pact

Image: British Prime Minister Theresa May and US President Donald Trump
British Prime Minister Theresa May shakes hands with US President Donald Trump during their meeting at the Palace Hotel in New York City, on the sidelines of the 72nd United Nations General Assembly, on Sept. 20, 2017.Brendan Smialowski / AFP - Getty Images

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By Reuters and NBC News

LONDON — Prime Minister Theresa May has reaffirmed Britain's commitment to a 2015 Iran nuclear deal in a telephone conversation with President Donald Trump ahead of a key U.S. decision on whether Tehran has stuck to the terms of the pact.

Trump has often cast doubt on the future of the Joint Comprehensive Plan of Action (JCPOA), which sought to curb Iran's nuclear program in return for lifting most Western economic sanctions.

"The [prime minister] reaffirmed the U.K.'s strong commitment to the deal alongside our European partners, saying it was vitally important for regional security," said a statement from May's office following the call on Tuesday evening.

"[The prime minister] stressed that it was important that the deal was carefully monitored and properly enforced."

In contrast, a White House statement on the phone call said Trump "underscored the need to work together to hold the Iranian regime accountable for its malign and destabilizing activities, especially its sponsorship of terrorism and its development of threatening missiles."

Government officials have told NBC News that the president is preparing to declare that the international accord with Iran is no longer in America’s national security interests, making a symbolic reversal of another of his predecessor’s signature initiatives but one that may largely leave the policy in place.

The White House press secretary, Sarah Huckabee Sanders, said Friday that the announcement of a new comprehensive strategy would happen “in the coming days” and would look at “all the bad behavior” of Tehran, not just its nuclear program.

Missiles are displayed as Iranian President Hassan Rouhani attends an armed forces parade in Tehran, IranReuters file

In a separate statement, Britain's Foreign Office said Iran had upheld its nuclear commitments, adding to international pressure on Trump not to jeopardize security in the region.

"The nuclear deal was a crucial agreement that neutralized Iran’s nuclear threat," foreign minister Boris Johnson said.

"It was the culmination of 13 years of painstaking diplomacy and has increased security, both in the region and in the U.K. It is these security implications that we continue to encourage the U.S. to consider."

Johnson spoke by telephone with U.S. Secretary of State Rex Tillerson and Iranian Foreign Minister Javad Zarif on Tuesday and will on Wednesday meet the head of Iran's nuclear agency in London to press for continued compliance with the deal.

May and Trump also discussed the need for Britain, the United States and others to work together to counter destabilizing Iranian activity in the region, May's office said.

Related: Is U.S.-U.K. Relationship still 'Special' After Trump Spats, Shock Vote

Britain and the United States are two of eight signatories to the deal, along with Iran, China, France, Russia, Germany and the European Union.

China, Russia and the European states have already expressed their continued support for the deal, while Iran has said Trump would not be able to undermine the pact.

If Trump declines to certify Iran's compliance, U.S. congressional leaders would have 60 days to decide whether to reimpose sanctions on Tehran suspended under the agreement.

Earlier, the White House said Trump would make an announcement later this week on an "overall Iran strategy", including whether to decertify the nuclear deal.

May's office said she agreed with Trump that their teams should remain in contact ahead of the decision on recertification.