US President Donald Trump, Jan. 4, 2018. Photo: Reuters / Kevin Lamarque.

US President Donald Trump was expected to decide on Thursday whether to extend sanctions relief to Iran under the 2015 nuclear deal as major European allies implored Washington to preserve the landmark arms control pact.

Under Secretary of State Steve Goldstein told reporters he expected Trump to decide on whether to continue sanctions relief for Iran on Thursday but was not sure if the decision would be announced Thursday night or Friday.

A move to reimpose sanctions would effectively torpedo the agreement reached between Iran and five major powers under which Tehran pledged to rein in its nuclear program in return for some easing of the economic restrictions imposed on it by the United States, the United Nations and the European Union.

In a telephone call with Trump on Thursday, French President Emmanuel Macron stressed the importance of abiding by the nuclear deal and, in an apparent effort to win the US president over, emphasized the need to enforce it rigorously.

“The proper implementation of the agreement should be accompanied by a strengthened dialogue with Iran on its ballistic program and its regional policy, in order to guarantee better stability in the Middle East,” the French presidency said in a statement on the call.

Two senior US officials told Reuters on Wednesday that Trump’s top advisers were recommending that he not reimpose sanctions on Iran that were lifted under the nuclear agreement.

However, Trump, who has previously vowed to scrap the nuclear pact, was privately expressing reluctance to heed the advisers, the officials said.

In one possible compromise, Trump could choose not to reimpose the sanctions that were eased under the nuclear deal but could slap other punishments on Iran, a pattern he has followed over the last year.

One US official said on Wednesday that if Trump waived the key sanctions under the deal, the administration would impose new, targeted measures against Iranian businesses and people.

US Treasury Secretary Steve Mnuchin said on Thursday that he expected Trump to impose new sanctions on Iran, without addressing what he would decide on the nuclear deal’s sanctions.

“I am expecting new sanctions on Iran,” Mnuchin told reporters. “We continue to look at them. We’ve rolled them out and I think you can expect there will be more sanctions coming.”