UNITED NATIONS — President Trump, who recently had Ted Nugent, Sarah Palin and Kid Rock over for a White House dinner, is planning to host 14 diplomats from around the world for lunch on Monday.
The diplomats are members of the powerful United Nations Security Council, an eclectic mix of America’s friends and rivals, and plenty of skeptics. Their guide to the White House is Mr. Trump’s outspoken envoy, Nikki R. Haley.
Halibut is on the menu, and a cheese soufflé, which one Council diplomat hoped would not be the most substantial part of the White House visit. As of Sunday, it was unclear who else the Council members would see, and whether Secretary of State Rex W. Tillerson would meet them.
The White House meeting follows a series of slights by the Trump administration toward the United Nations — and toward the idea of international cooperation in general. They include the administration’s antipathy to the climate agreement and the nuclear deal with Iran, its funding cuts to the United Nations population agency, and the broader funding cuts it has proposed for the world body.
The lunch guests will include envoys from Russia and China, the countries arguably most critical to the Trump administration as it faces tests over Syria and North Korea. Both crises are sure to come up.
Several diplomats are likely to raise the subject of the Israeli-Palestinian conflict, as well, even though Ms. Haley has tried to sideline it as a regular item on the Security Council’s agenda, instead describing Iran as the bigger threat to the region.
For a president who has promised an “America first” approach to dealing with world affairs, this is the first opportunity, behind closed doors, for Council diplomats to gauge Mr. Trump’s actual approach to the United Nations.
The United States is the organization’s largest single funder and, as such, its most powerful member.
The visit is potentially an opportunity for Ms. Haley to show to fellow Council diplomats that she can deliver the White House, just as it is a way for her to show how much the United States matters to the United Nations.
“There has been a lot of talk about China supplanting the U.S. as the top diplomatic dog at the U.N. since Trump’s election,” said Richard Gowan, a fellow at the European Council on Foreign Relations. “But at the end of the day, the Council’s school outing to Washington makes it clear that it is still at Washington’s beck and call.”
The lunch, expected to last 90 minutes, is part of a daylong visit by the members of the Security Council to Washington. It is to include meetings with members of Congress, although several Council diplomats said they had not been told which lawmakers.
The lunch menu, shared with diplomats ahead of time, was capped with a pineapple brioche pudding for dessert.
“Particularly this week, with everything on his plate, that he would take time out and have a conversation with the Security Council is a sign that he’s open to listening to them,” said Nancy Soderberg, a former ambassador to the United Nations during the Clinton administration. “It’s frankly surprising. It’s a testament to Nikki Haley’s increasing prominence within the administration.”
The visit by Council members comes days after Mr. Trump met for the first time with the United Nations secretary general, António Guterres. Their talk lasted less than 20 minutes and came after a longer meeting between Mr. Guterres and Lt. Gen. H. R. McMaster, the national security adviser, said the United Nations spokesman, Stéphane Dujarric.
“It’s an important relationship, and we are very pleased that the meeting happened,” Mr. Dujarric said of the meeting with General McMaster.
They agreed to meet again “in the near future,” Mr. Dujarric added.
The Security Council has visited the White House under previous administrations. Late last year, when the members of the Council were meeting with other senior White House officials, President Barack Obama joined them for what was supposed to be a quick meet and greet and ended up staying and talking for about 40 minutes on a range of issues on the Council’s agenda, according to diplomats who attended.
The idea of a meeting with Mr. Trump came from Vitaly I. Churkin, the former Russian ambassador, who died in February. He brought it up this year during the Council’s first meeting with Ms. Haley after she had been appointed the United States ambassador.