U.S. Ambassador to the United Nations Nikki Haley says that President Donald Trump is strengthening his ability to resolve the North Korea nuclear crisis by threatening to abandon the nuclear deal with Iran.

Haley is defending Trump’s decision not to certify Iran’s compliance with the deal. Trump’s critics argue he’s undermining U.S. credibility and options for diplomacy because North Korea will determine the U.S. doesn’t honor its commitments.

But Haley says that argument is “just wrong.” She says it’s the opposite. Haley says failing to fix the 2015 deal with Iran would send the message that the United States “can be bought by a bad deal” that doesn’t actually eliminate the nuclear threat.

Haley is speaking to an annual dinner of the conservative Heritage Foundation.