Donald Trump is poised to decertify the Iran nuclear deal, a senior official told Reuters Thursday, a move Trump called “the calm before the storm” at a White House dinner that night.

As a candidate, Trump regularly decried the 2015 agreement brokered by Barack Obama and many of America’s closest allies, calling it the “worst deal ever” and “an embarrassment to the United States.”

Despite recertifying the deal twice since January (the president has to do this every 90 days), multiple reports suggest Trump will reject the deal ahead of the next deadline on Oct. 15, claiming Tehran has violated the spirit of the deal.

Trump gave a hint of his plans at a Thursday meeting with military leaders in Washington.

“The Iranian regime supports terrorism and exports violence, bloodshed, and chaos across the Middle East,” Trump said. “That is why we must put an end to Iran’s continued aggression and nuclear ambitions. They have not lived up to the spirit of their agreement.”

“Maybe it’s the calm before the storm,” he added.

When pressed on what he meant, Trump said, “You’ll find out.”

If the White House rejects the deal, Congress would have 60 days to decide whether to reimpose sanctions.

France, Britain and Germany have all urged Trump not to abandon the deal, as has his own Defense Secretary James Mattis, who said keeping the accord was in U.S. national security interests.

General Joseph Dunford, chairman of the Joint Chiefs of Staff, warned last month decertification would hit U.S. credibility, while Ben Rhodes, a foreign policy advisor to the Obama administration, said Thursday, “Trump is lying. Iran is complying with the deal. Everyone — including his own Administration — has verified that fact.”