The president boasted that he's accomplished more during his time in office than nearly any previous administration - a claim that drew immediate laughter from the assembled diplomats and other world leaders.
In regard to Iran, the president called on world leaders to join the U.S.in isolating and sanctioning Tehran until the Islamic republic stops spreading terrorism and working to build a nuclear arsenal.
Wednesday's meeting highlighted a rift between the United States and its European allies over the Iran nuclear deal.
More than a few observers have hinted that Trump's comment about Rouhani could have been sarcastic, though.
"The Iran deal was a windfall for Iran's leaders".
"They want fame, they want money, they want whatever", he added of his accusers. Multilateralism is under fire precisely when we need it most.
The core US sanctions that seek to choke off Iran's oil exports, the lifeblood of its economy, will resume in early November, and Trump promised that "after that the United States will pursue additional sanctions, tougher than ever before, to counter the entire range of Iran's malign behavior".
That threat came just a day after the five remaining world powers that signed the nuclear deal announced they'd set up a special payment system to continue trade with Iran.
Far before he ever launched his presidential campaign, Trump spent years warning that the world was laughing at the actions of other American politicians.
"I've had numerous accusations about me", Trump said. "I ask all members of the Security Council to work with the United States to ensure the Iranian regime changes its behavior and never acquires a nuclear bomb". "President Trump's been clear about that and clear-eyed about that since the very beginning".
President Trump defended his "America First" agenda in a speech to the United Nations General Assembly on Tuesday, in effect spiking the football at what his secretary of state described as the "Super Bowl of diplomacy".
He said that Iran has lived up to its commitments under the JCPOA, and so should other signatories to the deal.
He said the deal was a "windfall for Iran's leaders", and said that the deal allowed Iran to increase its defence budget by "40 per cent".