WASHINGTON — President Trump welcomed Poland’s nationalist president to the White House on Wednesday with an elaborate show of support, promising more American troops, defending Warsaw’s record on democracy and staging a rare and showy F-35 jet flyover to mark their friendship.
In his latest embrace of Europe’s nationalist surge, Mr. Trump stood side by side with President Andrzej Duda and their wives on the South Lawn of the White House staring into the sky and waving as the Marine warplane roared overhead, buzzed around the Washington Monument and then headed back for a second pass.
A jet flyover above the White House is highly unusual, but Mr. Trump has agitated without success to hold a military parade down Pennsylvania Avenue and clearly relished showing off the state-of-the-art aircraft that Poland has agreed to buy. The flyover, however, startled many in the streets of Washington who did not know it was coming and, in some cases, pointed to the sky with worried looks or even started running.
“Moments ago we witnessed that impressive flyover of this cutting-edge F-35 as it flew over the White House and actually came to a — pretty close to a halt over the White House,” the president gushed afterward in the Rose Garden. “I would say: ‘What’s wrong with that plane? It’s not going very fast.’ But it is an incredible thing when you can do that. That plane can land dead straight and it is one of the few in the world that can do that.”
The flyover was part of a flourish of support for Mr. Duda, who has been ostracized by some other European leaders for actions considered anti-democratic. Mr. Trump made a point of signing an agreement to send an additional 1,000 American troops to Poland as a hedge against Russian adventurism in the eastern stretches of Europe, bolstering about 4,500 already there on a rotating basis.
But Mr. Trump fell short of agreeing to establish the permanent American military presence that Poland has sought. Polish leaders have been so eager for such a presence that they even offered to name a base Fort Trump, an unabashed appeal to the president’s known predilection for branding everything from buildings to neckties to steaks with his name.
Asked about the name on Wednesday, Mr. Trump did not reject it even as he acknowledged that it would draw scorn. “That is up to them,” he said. “That is all I’d need, Fort Trump. And you people would have a field day with that, right?”
Mr. Duda nonetheless portrayed the extra deployment as a major advance for Poland, calling it an “enduring presence” even if not a permanent one.
“There is a multitude of forums in which the United States is going to be gradually ever more present in our territory from the military standpoint,” he said. “And this will encompass different fields of cooperation.”
The presence of American troops in Poland and elsewhere in the former Soviet orbit has been a delicate one for years. After Russia’s incursion into Ukraine and annexation of Crimea in 2014, the United States and NATO allies sent small units of troops to Poland and the Baltic States on a rotating basis as a deterrent to any further moves by Moscow, a reminder that those nations were now under the protection of the North Atlantic alliance’s all-for-one defense umbrella.
While American and Polish officials are still discussing the idea of a permanent base, which would most likely require congressional approval, they have worked to strengthen their military partnership in other ways. Last year, American forces started flying unarmed Reaper surveillance drones from a Polish base in the country’s northwest.
“It’s a good idea because Russia constitutes a genuine security threat,” Daniel Fried, a former United States ambassador to Poland, said of the latest deployment. “Basing forces in Poland is intended to demonstrate to the Russians that this is not open territory to screw around with.”
But Julianne Smith, a former adviser to Vice President Joseph R. Biden Jr. and now a fellow at the Bosch Academy in Berlin, said the dispatch of just 1,000 more troops amounted to a major disappointment for Mr. Duda’s government.
“Even for a country like Poland that has done everything possible to establish a friendly and constructive relationship with Trump, including purchasing F-35s, the message from Trump is clear: ‘The United States is unwilling to do more for your security. You’re on your own,’” she said.
The F-35 flyover was so unusual that officials could not immediately come up with a precedent. A spokesman for the Air Force said it had no record of a White House flyover before. Although there have been flyovers during presidential inaugurations, the spokesman said the last one was in 1949 for Harry S. Truman.
Plans for a flyover at Mr. Trump’s inauguration in January 2017 were scotched because of weather. But the president was clearly excited about Wednesday’s display and even invited the Marine pilot to come to the White House later in the day for a reception for Mr. Duda.
Mr. Trump said that the additional troops would be redeployed from Germany, leaving the overall number in Europe the same, but the Pentagon later said no decision had been made about where the troops would come from. Mr. Trump said that 52,000 American troops remain in Germany, although the Defense Department says it is actually about 33,000. Mr. Trump once again excoriated Germany for not spending enough on its own defense.
On the other hand, he had nothing but praise for Mr. Duda and his government despite its actions in recent years to consolidate power at the expense of democratic institutions built up in the years since the collapse of communist rule. Among other things, Mr. Duda’s government sought to purge judges to assert control of the Supreme Court, drawing rebukes from elsewhere in Europe.
“I’m not concerned,” Mr. Trump said. “I know the president very well. I know the people and the leadership of Poland very well. I’m not concerned at all.” He added: “They don’t want to backslide. They won’t backslide.”
The scene was reminiscent of Mr. Trump’s meeting last month with Viktor Orban, the prime minister of Hungary whose authoritarian trend has been likewise criticized elsewhere in Europe. Mr. Trump praised Mr. Orban, who has vowed to build “an alternative to liberal democracy,” as a “highly respected” leader who “has done a tremendous job.”
Mr. Trump has also been a strong ally of Mr. Duda and Poland’s nationalist Law and Justice party, which was elected in 2015. He visited Warsaw in July 2017 and made a speech there that he recalled with nostalgia and self-praise on Wednesday, and he hosted Mr. Duda at the White House last September, as well.
“What they’ve done with the country over the last five years has been something that the world has watched and the world has marveled at,” Mr. Trump said.
Mr. Trump said he might make a return visit to Poland in September and suggested Poland might eventually be admitted into the United States visa regime along with other close allies — a prospect other presidents have dangled over the years, as well, without following through.
Mr. Duda rejected criticism of his government. “There is no problems with democracy in Poland. Really,” he said. “Everything is excellent.”
Added Mr. Trump, “That’s what I hear.”