President Donald Trump will embark on a whirlwind series of meetings next week at the United Nations General Assembly to make two big asks of the world: Stand with us against North Korea, and hold the line against Iran’s nuclear program.

Over the course of four days, beginning Monday, Trump will engage in a speed round of diplomacy that may test his patience for the notoriously factionalised, lethargic institution as well as his preference for one-on-one dealmaking in which the U.S. always holds the strongest hand.

“Next week is not going to be short on topics,” the U.S. ambassador to the United Nations, Nikki Haley, told reporters at the White House on Friday. She acknowledged that foreign leaders are curious about how the unpredictable U.S. President will maneuver. “They are all very anxious to hear what he has to say,” Haley said. “And I think that he will make quite an impact.”

Trump’s appearance at the UN — highlighted by an address Tuesday before the world body — is his biggest moment on the world stage since taking office. There is far more at stake than at the two economic summits in Europe he attended earlier this year. As he welcomes leaders from nearly 200 nations to his home town of New York, he’ll press them to join U.S. efforts to constrain missile and nuclear programs in both North Korea and Iran.

Tensions have risen sharply with both nations since Trump took office and assumed a more confrontational posture than his predecessor, Barack Obama.

Major Speech

“The world is still trying to take the measure of this President,” said Jon Alterman, senior vice president of the Center for Strategic and International Studies. “For a number of leaders, this is going to be their first chance to see him, to judge him, to try to get on his good side.”

In New York, Trump will hold a series of individual and small-group meetings with leaders from the Mideast, Latin America, Africa and Europe. He’ll headline the UN secretary general’s reform campaign, a 120-nation initiative. He’ll also continue two traditions of U.S. presidents at the UN: the major speech, on Tuesday, and a diplomatic reception planned for Monday evening.

“I personally think he slaps the right people, he hugs the right people, and he comes out with the U.S. being very strong in the end,” said Haley, who has seen a draft of Trump’s address.

In addition to Trump and Haley, Vice President Mike Pence, Secretary of State Rex Tillerson, National Security Adviser H.R. McMaster, the President’s adviser and son-in-law Jared Kushner and his National Economic Council director, Gary Cohn, are all expected to attend events in New York next week. Two key foreign leaders will not be on hand: Russian President Vladimir Putin and Chinese President Xi Jinping.

Nuclear Crises

The North Korean and Iranian nuclear programs are foremost on the President’s agenda. North Korea test-fired a ballistic missile with the range to reach Guam early on Friday, its latest in a series of provocations, and the Trump administration is seeking to extend and strengthen the Iranian nuclear deal that Obama signed and Trump has repeatedly maligned.

Trump will discuss the North Korea crisis over lunch with the leaders of South Korea and Japan. McMaster said Friday that the world is “out of time” to stop North Korea from becoming a nuclear state.

“What we have to do is call on all nations, call on everyone to do everything we can to address this global problem short of war,” he told reporters at the briefing. McMaster and Haley both insisted that the U.S. does have military options in the dispute, contrary to conventional wisdom that the city of Seoul’s vulnerability to a North Korean counterattack rules out the possibility of a strike.