PALM BEACH, Fla. — President Donald Trump opens a high-stakes summit Thursday with Chinese President Xi Jinping, with the urgent threat of North Korea’s nuclear ambitions and tensions over trade on the agenda for the first in-person meeting between the leaders of the world’s two largest economies.

The leaders were arriving in South Florida separately Thursday afternoon for the summit at Trump’s Mar-a-Lago estate, a location the White House said was selected to give the two days of discussions a more relaxed feel.

Xi landed in West Palm Beach, Florida, and was greeted by Secretary of State Rex Tillerson. Trump and Xi, joined by their wives, were slated to attend a welcome dinner Thursday night, followed by policy discussions on Friday.

Both as a candidate and president, Trump has taken an aggressive posture toward China, labeling Beijing “tremendous problem” and arguing that lopsided trade deals with China shortchange American businesses and workers. Last week, the president predicted in a tweet that his meeting with Xi would be “very difficult.”

The White House has downplayed expectations for a breakthrough on issues like trade and tariffs, insisting that the 24-hour summit is mostly an introductory meeting for the two leaders. And within Trump’s administration, there are still divisions over how to approach China.

According to U.S. and foreign officials, Treasury Secretary Steven Mnuchin and economic adviser Gary Cohn are leading the charge for boosting bilateral relations with China and exploring the potential for greater economic cooperation. But economic adviser Peter Navarro, author of the book “Death by China: Confronting the Dragon — a Global Call to Action,” prefers trying to isolate China, in keeping with Trump’s “America First” mantra.

Patrick Cronin, a China expert with the Center for a New American Security, said the Trump administration does not have “a reconciled trade and economic policy yet, and the differing views on China in the White House underscore that.”

Ahead of the summit, Trump signed a pair of executive orders focused on reducing the U.S. trade deficit. The moves appeared to be a shot at China, which accounted for the vast bulk — $347 billion — of last year’s $502 billion trade deficit. Chinese exports to the U.S. totaled some $388.1 billion last year.

Anthony Ruggiero, an East Asia expert at the Foundation for Defense of Democracies, said China may be may be more willing to accommodate Trump on trade and economic issues than on regional security issues, including North Korea. Xi, a shrewd political operator, is unlikely to want to rock the boat ahead of a Communist Party conclave later this year that will install new leadership.

The urgency about North Korea is expected to be at the forefront of the leaders’ discussions. A senior White House official said this week that the “clock has now run out” on Pyongyang, though officials have not detailed what steps Trump is willing to take to halt North Korea’s nuclear ambitions.

Like his predecessors, Trump is pressing China to exert more economic pressure on North Korea, though there is no sign he will be any more successful than past American presidents. In an interview last week with the Financial Times, Trump said that if China doesn’t take a tougher stand, the US is prepared to act alone.

Xi is also expected to seek assurances that Trump will not interfere in the territorial dispute over the South China Sea or question the “One China” policy by reaching out to Taiwan’s leader again, as he did during the transition. The move infuriated Beijing, leading Trump to eventually reiterate his commitment to the decades-old policy.

Previous White Houses have held China accountable for its human rights record, something this administration has made very little mention of, whether in China or elsewhere. It also remains to be seen whether the Obama administration’s deal with Beijing to curb Chinese cybertheft for economic gain and its hacking of U.S. companies will be addressed.