Since taking office in January, Trump has upended U.S. foreign policy, slashing foreign aid, imposing tariffs on friend and foe alike and cultivating warmer - if volatile - relations with Russia.
At the same time he has sought, so far with only limited success, to solve some of the world's most intractable conflicts.
Some 150 heads of state or government are expected to address the chamber this week, including Trump, who is the second scheduled speaker after the session opens at 9 a.m. EDT (1300 GMT).
Trump will speak eight months into a second term marked by severe aid cuts that have sparked humanitarian worries and have raised doubts about the U.N.'s future, prompting U.N. Secretary-General Antonio Guterres to try to trim costs and improve efficiency.
White House officials have yet to provide guidance on what Trump will say.
But according to planning documents reviewed by Reuters, the Trump administration plans to call this week for sharply narrowing the right to asylum, seeking to undo the post-World War Two framework around humanitarian protection.
Trump's more restrictive stance would include requiring asylum-seekers to claim protection in the first country they enter, not a nation of their choosing, a State Department spokesperson said.
Guterres and Trump are expected to meet formally for the first time since Trump returned to office in January.
Trump describes the U.N. as having "great potential" but says it has to get its "act together." He has maintained the same wary stance on multilateralism that was a hallmark of his first term from 2017 to 2021 and also accused the world body of failing to help him try to broker peace in various conflicts.
CALLS FOR A PALESTINIAN STATE
The General Assembly takes place as the war between Israel and Hamas approaches its second anniversary on October 7. Israeli Prime Minister Benjamin Netanyahu is due the address the General Assembly on Friday.
Dozens of world leaders gathered on Monday to embrace a Palestinian state, a landmark diplomatic shift that faces fierce resistance from Israel and its close ally the United States.
The most far-right government in Israel's history has declared there will be no Palestinian state as it pushes on with its fight against militant group Hamas in Gaza following the October 7, 2023, attack on Israel that killed some 1,200 people.
Israel has drawn global condemnation over its military conduct in Gaza, where more than 65,000 Palestinians have been killed, according to local health authorities.
Ukrainian President Volodymyr Zelenskiy and Russian Foreign Minister Sergei Lavrov will also address the General Assembly.
Trump and Zelenskiy are expected to meet on Tuesday.
The U.S. president will also hold a bilateral meeting with Argentina's Javier Milei and a multilateral meeting with the leaders of Qatar, Saudi Arabia, Indonesia, Turkey, Pakistan, Egypt, the United Arab Emirates and Jordan.
