WASHINGTON — President Donald Trump on Friday said that he will decertify Iran’s compliance with the 2015 nuclear deal and added that he might withdraw from the international agreement if Congress and U.S. allies do not strengthen it.

advertisement | advertise on newsday

In a White House speech to announce the shift in U.S. policy, Trump accused Iran of “not living up to the spirit of the deal,” but stopped short of actually “tearing up the deal” as he has often threatened to do.

“Today I am announcing our strategy with several major steps we’re taking to confront the Iranian regime’s hostile actions and to ensure that Iran never — and I mean never — acquires a nuclear weapon,” he said.

Trump said he is directing his administration to work with Congress and U.S. allies to come up with a solution to ensure the Iranian regime no longer destabilizes the region, terrorizes the world or continues on a path to developing a nuclear weapon.

But if Congress, which enacted a law requiring the certification of the deal every 90 days, does not pass new legislation to toughen enforcement of the deal and to take steps to curb Iran’s activities, Trump said, “The agreement will be terminated.”

He added, “It is under continuous review, and our participation can be canceled by me, as president, at any time.”

Trump’s tough talk drew a mixed response abroad and in Congress.

Iranian President Hassan Rouhani said his country will “stick to” the deal, which he said was a multinational agreement that was not re-negotiable and could not be annulled by Trump as a leader of just one of the seven countries who signed it.

But Israeli Prime Minister Benjamin Netanyahu praised Trump for creating “an opportunity for fixing a bad deal.”

In a joint statement, British Prime Minister Theresa May, German Chancellor Angela Merkel and French President Emmanuel Macron urged the Trump administration and Congress to consider the possible consequences for the West’s security “before taking any steps that might undermine” the deal, including imposing sanctions on Iran that the agreement lifted.

In Moscow, a close ally of Iran, Russian President Vladimir Putin’s spokesman, Dmitry Peskov, warned that any move to spike the deal “would undoubtedly hurt the atmosphere of predictability, security, stability and nonproliferation in the entire world.”

advertisement | advertise on newsday

Senate Majority Leader Mitch McConnell (R-Ky.) and House Speaker Paul Ryan (R-Wis.) praised the president’s decertification and promised to take legislative action.

But Senate Minority Leader Chuck Schumer (D-N.Y.), who opposed the deal in 2015, said he agreed with Secretary of Defense James Mattis and Chairman of the Joint Chiefs of Staff Gen. Joseph Dunford “that it’s in our national security interest to keep the deal in place.”

The new strategy Trump announced includes three goals: To fix the deal and remove the expiration dates in it to prevent Iran from ever developing a weapon, to counter its ballistic missile program, and to curb Iran’s support for “terrorism and extremism.”

Trump also announced that the Treasury Department will impose sanctions on portions of Iran’s Revolutionary Guard Corps, its officials, agents and affiliates by designating them terrorist organizations under an existing executive order — and he invited other countries to join in.

“History has shown the longer we ignore a threat, the more dangerous that threat becomes,” said Trump, before detailing the history of terrorism and destabilizing actions going back to the overthrow of the shah in 1979.

advertisement | advertise on newsday

Secretary of State Rex Tillerson said the administration has reached out to other nations in the deal about the president’s concerns. He said officials also have talked to members of Congress to discuss the next steps to fix the deal.

The Senate Foreign Affairs Committee chairman, Sen. Bob Corker (R-Tenn.), and Sen. Tom Cotton (R-Ark.) already have begun writing legislation.

“The president on many occasions talked about either tearing the deal up or fixing the deal. We think this is the best platform for fixing this deal,” Tillerson said.

After the speech, Trump spoke to reporters on the South Lawn as he and first lady Melania Trump prepared to board Marine One for a visit to the U.S. Secret Service training center in Beltsville, Maryland.

Asked why he didn’t just rip up the deal, Trump said, “So what we’ve done is, though the certification process we’ll have Congress take a look at it, and I may very well do that [rip up the deal]. But I like a two-step process better.”

With Emily Ngo and AP