President Donald Trump speaks to the United Nations General Assembly, Tuesday, Sept. 19, 2017, in New York. Associated Press/Evan Vucci President Donald Trump on Tuesday slammed the Iran nuclear deal during his first address to the United Nations General Assembly, calling the pact an "embarrassment" and "one of the worst and most one-sided transactions the United States has ever entered into."

"I don't think you've heard the last of it, believe me," Trump said.

Trump, addressing more than 150 international delegations, called the Iranian government an "economically depleted rogue state" whose main export is violence, and urged the "entire world to join us in demanding that Iran's government end its pursuit of death and destruction."

Trump said world leaders cannot honor the Iran deal if it "provides cover" for the country to eventually produce nuclear weapons.

"It is time for the regime to free all Americans and citizens of other nations that they have unjustly detained," Trump said. "And above all, Iran's government must stop supporting terrorists, begin serving its own people, and respect the sovereign rights of its neighbors."

Trump has long complained about the Iran nuclear deal throughout his presidential campaign and into the early months of his presidency. Despite his reservations, however, Trump has twice certified Iran's compliance with the nuclear agreement, which must be reviewed every 90 days before US sanctions are reinstated.

The agreement was negotiated in 2015 by the Obama administration and the governments of Britain, Germany, France, China, and Russia. The agreement restricted Iran's nuclear activities in exchange for the easing of economic sanctions.

Yet Trump has repeatedly said he believes Iran is violating the agreement. Shortly after the last recertification in July, Trump told The Wall Street Journal, "If it was up to me, I would have had them noncompliant 180 days ago."

Iranian President Hassan Rouhani said during a meeting with media executives before Trump's address on Tuesday that Iran has fully complied with the agreement, The Washington Post reported. He added that the US "will certainly sustain losses" if it "tramples" upon the deal.

"Everyone will clearly see that Iran has lived up to its agreements and that the United States is therefore a country that cannot be trusted," Rouhani said. "We will be the winners."