President Donald Trump plans to announce next week that he will de-certify the international nuclear deal with Iran, the Washington Post reported.

The report Thursday night, based on interviews with unnamed people who have been briefed on the White House strategy, said that Trump has decided to make initial steps toward distancing the United States from a deal it brokered in 2015 under then president Barack Obama that offers the Islamic republic sanctions relief in exchange to its scaling back of some elements of its nuclear program. At least one source called this a move to “de-certify” the deal.

The people interviewed by the Post said that Trump believes the deal is not in the national interest of the United States. He will kick the issue to a reluctant Congress, they added. Donald Trump has accused Iran of not living up to the “spirit of the agreement” of its nuclear deal – a reference to its ballistic testing, conventional arms procurement, overseas intervention and support for terrorism.

At a meeting of US military chiefs, including Defence Secretary Jim Mattis, Trump on Thursday told reporters: “You guys know what this represents? Maybe it’s the calm before the storm. Could be the calm, the calm before the storm.”

Asked what he meant by the reporters he had summoned to cover the meeting at the State Dining Room at the White House on Thursday evening, Trump said: “You’ll find out.”

The move reportedly eyed by Trump would mark the first step in a process that could eventually result in the resumption of US sanctions against Iran, potentially derailing the deal signed between Iran, the United States and five other nations despite opposition from Israel and several Sunni Muslim Arab countries.

But Trump would hold off on recommending that Congress reimpose sanctions, which would constitute a clearer break from the pact, according to four people familiar with aspects of the president’s thinking, the Post reported.

The decision would amount to a middle ground of sorts between Trump, who has long wanted to withdraw from the agreement completely, and many congressional leaders and senior diplomatic, military and national security advisers, who say the deal is worth preserving with changes if possible.

Israeli Prime Minister Benjamin Netanyahu has warned that the deal “paves Iran’s path” to nuclear offensive capabilities, also because the limitation it introduces on Iran’s nuclear efforts expire after 10 years. But Obama and other proponents of the plan said it was the best way to block Iran’s path to nuclear weapons, as it introduces an incentive to abandon their development.

This week, Mattis and Gen. Joseph F. Dunford Jr., the chairman of the Joint Chiefs of Staff, expressed qualified support for the deal during congressional testimony. And Mattis suggested he did not believe taking the step to de-certify would scuttle the agreement.

Trump criticised the Iran nuclear deal and called the Iranian government a “corrupt dictatorship” while addressing the United Nations General Assembly last month. Trump is expected to deliver a speech, tentatively scheduled for Oct. 12, laying out a larger strategy for confronting the nation he blames for terrorism and instability throughout the Middle East.

Officials cautioned that plans could still change, and the White House would not confirm plans for a speech or its contents. Trump faces an Oct. 15 deadline to report to Congress on whether Iran is complying with the agreement and whether he judges the deal to be in the U.S. national security interest.