Leaders from round the world gather for the U.N. General Assembly: A quick look at what’s on the table

The nuclear threat from North Korea and the plight of Myanmar's minority Muslims are among the many intractable challenges confronting world leaders as they begin high-level talks at the United Nations General Assembly on Tuesday.

President Trump, who makes his debut before the world body at 10:30 a.m., is attracting much of the attention from diplomats anxious to know what his "America first" approach will mean for international institutions and alliances that have been a bedrock of U.S. foreign policy for decades.

Trump has made his disdain known for what he regards as a bloated U.N. bureaucracy that relies too heavily on the generosity of the U.S. And his administration has staked out positions that are at odds with the U.N. on key issues such as climate change and the deal to curb Iran’s nuclear program.

But he is one of more than 100 heads of state and government expected to deliver speeches and take part in the meetings this week at U.N. headquarters in New York. Here are some of the issues that are expected to take up a majority of their attention:

Live updates: The U.N. and world await Donald Trump's first assembly »

North Korea

North Korea's reclusive leader, Kim Jong Un, has remained unfazed by successive rounds of U.N. sanctions and a chorus of international condemnation for his recent nuclear and missile tests. Trump has warned that he will bring “fire and fury” against the country if it continues to threaten the U.S. But experts see few good military or diplomatic options to rein in the rogue nation. A delegation from Pyongyang is scheduled to be at the U.N. this week, although Kim is skipping the annual gathering. So is Chinese President Xi Jinping, Kim's top ally.

A photo from North Korea’s official Korean Central News Agency is said to show an intermediate-range strategic ballistic rocket lifting off near Pyongyang on Aug. 29, 2017. (Korean Central News Agency / AFP/Getty Images)

(Korean Central News Agency / AFP/Getty Images)

Global warming

The gathering comes at a time of mounting concern about the effects of global warming. U.N. Secretary-General Antonio Guterres has made implementation of a landmark climate agreement reached in Paris in 2015 a priority, telling reporters last week that recent hurricanes and flooding “remind us that extreme weather events are expected to become more frequent and severe due to climate change.” But Trump has said the U.S. will pull out of the deal unless terms are reached that he considers more favorable to American economic interests.

Emissions rise from a factory at Broadwater in far northern New South Wales, Australia. (Dave Hunt / European Pressphoto Agency)

(Dave Hunt / European Pressphoto Agency)

Myanmar's Rohingya Muslims

More than 400,000 minority Muslims have streamed out of Myanmar in recent weeks, fleeing a violent military crackdown that followed insurgent attacks on military posts. The U.N.’s top human rights official has branded the bloodshed a “textbook example of ethnic cleansing,” but the response from the Security Council has been muted. Aung San Suu Kyi, the Nobel Peace laureate who is leading Myanmar’s first civilian government after a half-century of military rule, canceled plans to attend this year's General Assembly.

Rohingya refugees cross into the mainland after arriving in Bangladesh. (Allison Joyce / Getty Images)

(Allison Joyce / Getty Images)

Iran's nuclear program

Trump has also threatened to tear up the Iran nuclear disarmament accord negotiated by President Obama and other world leaders in 2015. Although the U.N.'s nuclear watchdog has found that Iran is complying with the restrictions imposed, the administration has argued that the Islamic Republic is violating the "spirit" of the deal. The parties that negotiated with Iran — Britain, China, France, Germany, Russia and the U.S. — are scheduled to meet Wednesday on the sidelines of the General Assembly. But there are no plans for Trump to sit down with Iranian President Hassan Rouhani, who will also be in New York.

Iranian President Hassan Rouhani attends an interview with state-run TV at the presidency office in Tehran. (The office of the Iranian Presidency / Associated Press)

(The office of the Iranian Presidency / Associated Press)

alexandra.zavis@latimes.com

Twitter: @alexzavis