NEW YORK — President Trump will make his United Nations General Assembly debut this week amid uncertainty on how his administration will handle rising North Korean aggression, a looming deadline to decide the future of the Iran nuclear deal and the U.S. position on withdrawing from or staying in the Paris climate accords.

Trump will focus much of his attention at the summit on reforming the U.N. itself, headlining a meeting on Monday with dozens of world leaders who signed onto his 10-point pledge to clean up an organization he once described as "a club for people to get together, talk and have a good time."

But the president will also face pressure to provide clearer answers to questions plaguing the international community and to affirm his commitment to the U.N., as he did with NATO earlier in this year.

"At first glance, you'd think that this would be sort of a train wreck or a potential major confrontation," said Stewart Patrick, senior fellow at the Council on Foreign Relations. "He's going into, in a sense, the belly of the beast in terms of globalism."

Patrick said there is "some room for optimism" that Trump may take a "constructive approach" to his first appearance at the U.N., however, particularly because of his surprisingly good relationship with U.N. Secretary General Antonio Guterres.

"He has aligned himself with the reform agenda of Secretary General Antonio Guterres," Patrick said of Trump. "They're sort of an odd couple, because Guterres is sort of a European socialist or a social democrat in some ways."

Guterres, the former prime minister of Portugal, has pledged to address the bureaucratic deficiencies of the body he took over earlier this year. His desire to cut waste and redirect resources has given him common ground with Trump, whom he met at the White House in April for their first official introduction.

"Guterres is very interested in deals, and he has wisely seen that the last thing that the U.N. needs is for the United States to take either a totally confrontational approach to the U.N. or just sort of cut it loose," Patrick said. "So I think he has kind of been trying to lay some groundwork for a constructive relationship with the U.S."

The day after his U.N. reform meeting, however, Trump will face the more high-profile task of addressing leaders from all 193 member states in the General Assembly. His speech will likely be widely scrutinized for hints of his administration's plans for North Korea and Iran, among other issues.

Pyongyang's increasingly aggressive pursuit of nuclear weapons capable of striking the American mainland has drawn sharp condemnation from the U.N. Security Council, of which the U.S. is a permanent member. Last week, the UNSC passed a fresh round of sanctions on North Korea aimed at curbing its access to oil and financial resources in response to its largest-ever nuclear test on Sept. 3.

Although U.S. Ambassador to the U.N. Nikki Haley described the new sanctions as "by far the strongest measures ever imposed on North Korea," Trump said just hours later that the sanctions are " just another very small step — not a big deal." The conflicting messages, which Haley downplayed on Friday during an appearance at the White House, have contributed to a sense of confusion about how the Trump administration plans to counter North Korea's nuclear push.

"The goal on North Korea will be to assemble a coalition to apply unified coercive measures short of war, leaving the threat of escalation open as the only way to get China to move," said Charles Lipson, political science professor at the University of Chicago.

Trump has criticized China in the past for its failure to rein in Kim Jong Un, North Korea's elusive dictator, despite his tolerance of the Chinese trade practices he excoriated on the campaign trail.

Chinese President Xi Jinping is not expected to attend the U.N. summit this week, precluding any opportunity Trump may have had to discuss the North Korean situation with the Chinese leader, who he already knows personally from Xi's visit to Mar-a-Lago, Trump's Palm Beach, Fla., estate, earlier this year.

Patrick said Trump is unlikely to take China to task publicly at the UNGA, as he has done in the past, in order to preserve the option of leaning on China in the future.

"My suspicion is that he will be advised that there's not a whole lot to be gained from really going after China strongly," Patrick said. "But I think that he doesn't want to jeopardize Chinese assistance with the North Korea situation."

On Iran, Trump will confront questions about whether he plans to extend the life of the nuclear agreement his predecessor struck with Tehran, and which he has described as "the worst deal ever negotiated." The State Department must certify to Congress that Iran is still complying with the Joint Comprehensive Plan of Action, as the Iran deal is formally known, in mid-October, creating a clean opportunity for Trump to abrogate the agreement next month should he choose to follow through on campaign-era threats to do so.

The administration has not yet signaled whether Trump plans to recertify the JCPOA in a few weeks. But H.R. McMaster, Trump's national security adviser, told reporters at the White House on Friday that the president would discuss Iranian provocations with the leaders of France and Israel during separate bilateral meetings on Monday.

"While their conversations will be wide-ranging, we expect that Iran's destabilizing behavior, including its violation of the sovereignty of nations across the Middle East, to be a major focus," McMaster said.

And a report published over the weekend about the fate of the Paris climate accords has added another layer of uncertainty to Trump's U.N. appearance. Many of the leaders he will meet at the event, including French President Emmanuel Macron, are major proponents of the international climate change agreement and have previously criticized Trump's decision in June to withdraw from it. They could be eager to pounce on any sign of wavering on the U.S. commitment to leaving the accords.

While the Wall Street Journal reported on Saturday that the administration did not actually intend to pull out of the deal, White House officials have since denied the claim and said the U.S. will only "re-enter" the climate agreement under terms more favorable to the U.S. economy. What those terms could look like, and how the agreement will function moving forward, with or without the U.S., could become a topic of discussion among leaders at the UNGA.

Russian President Vladimir Putin is not expected to attend the summit this week, eliminating the possibility of a high-stakes confrontation with Trump like the one that dominated headlines at the G-20 gathering in Hamburg, Germany, in July.

But Russia's interference in other countries, such as its annexation of Crimea and its meddling in the U.S. presidential election last year, will likely loom large over the U.N. meeting and present challenges for Trump as he attempts to navigate the politically difficult terrain Russia creates for him.

"Russia is really going to be tricky for the president," Patrick said. "If this were a traditional Republican, I mean if this were Jeb Bush at the dais or John McCain at the dais, you would imagine a very staunch criticism of Russian interference in American elections, an attack on Russian repression, the creeping authoritarianism under Vladimir Putin, you would imagine a major attack on proxy intervention in Eastern Ukraine."

With Trump, however, Patrick predicted any indictment of Russia will come across as "less blunt."

Trump has struggled to overcome the controversy caused by a special counsel investigation into whether his campaign aided Russia in its efforts to sway voters in the 2016 election. While the president and his associates deny any such collusion took place, the broadening investigation into the campaign's Russian contacts has all but precluded any opportunity for Trump to initiate the kind of diplomatic opening with Moscow for which he advocated during the presidential race.

"The only question regarding Russia is whether the U.S. can engage in much discussion," Lipson said. "There are really two problems. One is that the two countries have few common objectives. The other is that Russia overplayed its hand in 2016, interfering in the U.S. election so obviously and clumsily that secret bilateral discussions are much harder and agreements nearly impossible."

Haley said Friday that Putin's absence will not prevent "serious discussions" from taking place with Russia's foreign minister about Syria, North Korea and Iran.