Prince William makes a surprise visit to Poland to thank troops.

Prince William made an unannounced trip to Poland on Wednesday to “personally thank” British and Polish troops supporting Ukraine’s armed forces as part of a two-day visit intended to highlight Britain’s support for Ukraine.

William arrived in Warsaw and then traveled to the southeastern city of Rzeszow, roughly 50 miles from Poland’s border, where he told troops that “everyone back home thoroughly supports you.”

He also met with the Polish defense minister, Mariusz Blaszczak, who called the visit a “great honor” and emphasized that British and Polish troops were working “side by side” to strengthen not just Poland’s security, but the security of NATO’s entire eastern flank.

Poland and the United Kingdom have been on the forefront of countries providing aid to Ukraine. Each pledged to send Western battle tanks earlier this year in an effort to coax other allies into doing the same, a move that proved successful. Poland’s president, Andrzej Duda, also said last week that his country would be the first NATO nation to give Ukraine fighter jets.

William was the latest high-profile figure to visit Rzeszow during the war. The city serves as a vital hub of Western military and humanitarian aid. President Biden visited American troops stationed there last year and traveled through the city’s airport on his way to Kyiv in February. And President Volodymyr Zelensky of Ukraine has also visited, bestowing the honorary title of “Rescuer City” on Rzeszow for its role in supporting Ukraine.

William was to meet Ukrainian refugees in Warsaw later Wednesday evening, according to a statement shared with Polish and British news media by Kensington Palace. On Thursday, he is expected to meet with Mr. Duda, but first, he is scheduled to lay a wreath at Warsaw’s Tomb of the Unknown Soldier, just as Queen Elizabeth II and Prince Philip did in 1996.