Former Secretary of State John Kerry and other top national security experts are backing an organisation aimed at defending the Iran nuclear deal, as Donald Trump determines for the first time whether to temporarily alleviate some restrictions on the country.

The deadline for Mr Trump to make his decision is on Thursday, the day before he is set to depart for his first trip abroad as president. During his presidential campaign, the US leader repeatedly called the accord with Iran “the worst deal ever”, and Vice President Mike Pence threatened to rip it up.

On his overseas trip, Mr Trump is likely to discuss issues involving Iran in Saudi Arabia and Israel. Israeli Prime Minister Benjamin Netanyahu urged members of Congress two years ago to reject the Iran deal, saying it would only feed an “Iranian terror machine”.

Under the 2015 agreement, Iran agreed to roll back its nuclear programme in exchange for the removal of certain restrictions. Roughly every 120 days following the implementation of the deal in January 2016, the US president must determine whether to issue waivers temporarily suspending some sanctions.

Those sanctions can be reimplemented if Tehran does not honour the agreement.

Last month in a letter to House Speaker Paul Ryan, Secretary of State Rex Tillerson said Iran had complied with its commitments through 18 April, but noted that the country continued to be a “leading state sponsor of terrorism.”

Mr Tillerson notified Mr Ryan that the president has directed a National Security Council-led interagency review to “evaluate whether suspension of sanctions related to Iran pursuant to the [Joint Comprehensive Plan of Action] is vital to the national security interests of the United States.”

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Meanwhile, several national security experts that served under President Barack Obama are fighting to protect the accord through the newly formed organisation ‘Diplomacy Works’.

“There are few better examples of the value of diplomacy than the Joint Comprehensive Plan of Action (JCPOA): it has blocked Iran’s pathways to a nuclear weapon and has made the United States and our allies safer,” the group said in its mission statement.

Jon Finer, former Chief of Staff and Director of Policy Planning at the State Department, told The Independent one of the goals of ‘Diplomacy Works’ is to “bring accurate, nonpartisan information about the deal at a time when the focus on Iran policy is increasing and there is widespread disinformation about what is in it and how it is working.”

Mr Finer is on the group’s Council of Advisors, which also includes Mr Kerry, one of the chief negotiators of the Iran deal; Antony Blinken, former Deputy Secretary of State; Nick Burns, former Under Secretary of State for Political Affairs; Puneet Talwar, former Assistant Secretary of State for Political-Military Affairs; Robert Malley, former Senior Adviser to the President for the Counter-ISIL Campaign; Jen Psaki, former White House Communications Director; and Jeff Prescott, former National Security Council Senior Director for Iran, Iraq, Syria and the Gulf.

While most were part of the Obama administration, Mr Burns served under President George W Bush.