Poland’s right-wing and largely ceremonial president, Karol Nawrocki, arrived in Washington on Wednesday for a meeting and lunch with President Trump, a visit that highlights divisions within the biggest economic and military power on the European Union’s eastern fringe.

Mr. Trump, who welcomed Mr. Nawrocki in the Oval Office and endorsed him before his election in June, has shunned Poland’s center-left government, which controls the country’s foreign and defense policy. In his so far fruitless pursuit of a peace deal between Russia and Ukraine, Mr. Trump has largely ignored Poland and other countries that border Ukraine and see Russia as a dangerous aggressor.

Mr. Trump’s meeting with Mr. Nawrocki, scheduled to begin at 11 a.m. Wednesday at the White House, has helped calm anxiety in Poland that its voice is not being heard. But it has also laid bare differences between Poland’s government, headed by Prime Minister Donald Tusk, a critic of Mr. Trump in the past, and right-wing political forces aligned with Mr. Nawrocki.

According to Polish media reports, Mr. Nawrocki rejected a request from the government that it be represented in his delegation traveling to the United States. Poland’s foreign minister, Radoslaw Sikorski, is also visiting Washington but not the White House.

That prompted public sniping this week between the Polish government and Mr. Nawrocki’s backers.

“There cannot be two foreign policies serving one country,” Pawel Wronski, the Polish foreign ministry spokesman, told a news conference on Tuesday in Warsaw. He said the ministry wished Mr. Nawrocki well in his meeting with Mr. Trump but urged him to stick to government policy.