US President Donald Trump can expect a large and enthusiastic crowd for a landmark speech in Poland on Thursday, thanks in part to local allies who are bussing in supporters from around the country.

Trump will take the stage at Warsaw's historic Krasinski Square, hoping that a sea of thousands -- perhaps tens of thousands -- of jubilant foreign fans will burnish his credentials as an admired and respected global statesman.

In that quest, the embattled US president will get a sizeable assist from Poland's ruling conservative party, which said it is laying on free buses to ferry in admirers.

"It is important that President Trump feel good about his visit to Poland," Stanislaw Pieta, a member of parliament for the Party of Law and Justice told the AFP.

Conservative Poles, he said, want to say "thank you" to the ideologically aligned US president, for opposing the "policy of demoralization and de-Christianization advocated by Western Europe."

Pieta and others in the Law and Justice party see the speech as an important event to consolidate the party's own grassroots support. He and his neighboring MPs are helping transport 500 people from the southern region of Bielsko-Biala to the capital alone.

A similar trend has emerged across the country, with Polish media suggesting that each party lawmaker has been told to provide 50 people, for a total crowd of 15,000.

Deputies from Czestochowa, also in the south, say they have filled eleven buses. From Lodz, central Poland, there are still a few seats left, but a local party official stressed the transport was free when asked.

Meanwhile in Warsaw -- the opposition-ruled Polish capital -- pro-Trump posters have popped up, urging people to "be at the center of things," to go and later enjoy a picnic organized by the ministry of defense.

Law and Justice senator Adam Bielan denied suggestions that Trump and his Polish allies were effectively renting a crowd, a practice that was common in Poland's communist past.

"There is no harm in organizing this transport. The same happens in the United States or in France" Bielan told AFP.

"We do not force anyone to come, we do not pay people for them to come... People want to see Trump for themselves, he's the most important man in the world."

Global stage, domestic audience

Trump's remarks are expected to focus on the Polish-US alliance and his vision for transatlantic relations and will take place on a square that memorializes the city's valiant uprising against Nazi occupation.

Politically, the White House hopes the event will bolster a relatively rare like-minded European government and serve as a counterpoint to critics at home, who accuse Trump of tarnishing America's reputation around the world.

Trump has a natural ally in Poland's anti-immigrant, pro-catholic ruling party which is also hostile to the media, but he is viewed extremely negatively across much of Europe.

Twenty-three percent of Poles say they have confidence in Trump's ability to do the right thing on global affairs, according to a recent Pew Research Center poll.

That figure is just 11 percent in Germany, the second and final stop on Trump's four-day European swing.

There, anti-globalization protestors are already amassing on the city of Hamburg, where Trump will attend a G20 meeting, and are planning a "welcome to hell" rally.

For the White House, the sight of flag-waving Polish acolytes could ease the perception that Trump's ability to travel has been curbed by the prospect of mass demonstrations.

His first foreign trip was to Saudi Arabia and a mooted state visit to the United Kingdom appears to have been put on the backburner.

A small gathering in Poland would be a political disaster for Trump, who is notoriously prickly about crowd sizes.

On the campaign trail and now in the White House he frequently declares his events to be the "biggest ever" in that venue.

The first days of his presidency was marked by a furious response to suggestions that his inauguration crowd was much smaller than that of Barack Obama eight years earlier.

Trump's Warsaw appearance is sure to draw further Obama comparisons.

In the 2013, before becoming president, Obama's speech at the Brandenburg Gate in Berlin drew an estimated crowd of 200,000.