The United States said on Wednesday it is weighing whether the Iranian nuclear deal serves its security interests even as Iran said it did not expect Washington to abandon the agreement.

A collapse of the 2015 deal, which U.S. President Donald Trump has called “an embarrassment” but which is supported by the other major powers that negotiated it with Iran, could trigger a regional arms race and worsen Middle East tensions.

Iranian President Hassan Rouhani vowed that his country would not be the first to violate the agreement under which Tehran agreed to restrict its nuclear program in return for the loosening of economic sanctions that had crippled its economy.

“We don’t think Trump will walk out of the deal despite (his) rhetoric and propaganda,” Rouhani told reporters on the sidelines of the U.N. General Assembly gathering of world leaders. He also ruled out the idea of renegotiating the pact.

Trump told reporters he had made a decision on what to do about the agreement but would not say what he had decided.

Matters were no clearer after Iran and the world powers that negotiated the deal – Britain, China, France, Germany, Russia and the United States – met for talks that a European source said included a long discussion between the U.S. and Iranian foreign ministers.

It was the first time that the two men, U.S. Secretary of State Rex Tillerson and Iranian Foreign Minister Mohammad Javad Zarif, had met since Trump took office on Jan. 20.

The EU’s foreign policy chief, Federica Mogherini, said all sides believed there had been no violations to the deal but she was unable to say after the roughly hour and 20-minute meeting whether the United States would stick to it.

“We already have one potential nuclear crisis. We definitely (do) not need to go into a second one,” she told reporters, alluding to North Korea’s pursuit atomic weapons.

Asked if the United States had committed to staying in the pact, she appeared to be at a loss and said: “Another question.” Tillerson told reporters Trump did not wish to leave the Iran nuclear issue to the next president.

“That is the reason he is very, very carefully considering the decision of whether we find the JCPOA to continue to serve the security interests of the American people or not,” he said, referring to the pact formally called the Joint Comprehensive Plan of Action.

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The U.S. president, who on Tuesday called the deal “one of the worst and most one-sided transactions the United States has ever entered into,” told reporters he had made up his mind whether to keep the pact but declined to disclose his decision.