He again dismissed the Iran nuclear accord as terrible for America, saying, “This is the worst deal. We got nothing.” The nuclear deal with Iran gave sanctions relief to the country in exchange for curbs on its nuclear program.

“We did it out of weakness when actually, we have great strength,” said Trump, who added, “We will see what happens pretty soon.”

Trump must announce his decision on whether to certify Iran’s compliance by the end of the week, as it is required that every 90 days the president notify Congress as to whether he believes Iran is complying with the accord and if the lifting of sanctions is in the interest of the American people.

Trump has twice certified the accord, but said the next deadline on Sunday is the crucial one. Several US officials have said Trump might not choose to certify the accord this time.

Trump would be defying the opinion of some of his top advisers, European countries and the International Atomic Energy Agency, if he chooses not to certify.

A decision to decertify the deal would leave it at grave risk, with the US Congress having 60 days to decide whether to re-impose specific sanctions on Tehran that were lifted under the diplomatic pact.

Congress will have to try to address “the main GOP complaint that after 10 years that Iran is put on a definite pathway to nuclear development,” The Washington Post’s Karoun Demirjian explains. “The problem is, they don’t have buy-in from Democrats.”

“Either you blow up the deal or you don’t blow up the deal; we know they don’t want to blow up the deal, which means you get one shot to actually change the things you don’t like about it. Otherwise you become the boy who cried wolf,” said Demirjian, and he added, “If you do this every three months, people aren’t going to believe you’re actually going to change anything.”

Some say that an unbending message to Iran would make North Korea take notice. They argue that getting tough on Tehran gives Trump a chance to prevent them from developing nuclear weapons.

Proponents of the deal argue there is no evidence Tehran is breaching the deal. In fact, the head of the UN’s atomic agency, Yukiya Amano, affirmed Iran’s commitment to the 2015 nuclear deal on Monday.