Republican presidential nominee Donald Trump on Wednesday told a group of Polish-Americans that the European nation would have a reliable ally in the U.S. if he wins the November election, Bloomberg reports.

Trump at Chicago’s Polish National Alliance credited Poland with staying “up to date” on its payments to the North Atlantic Treaty Organization. He has accused other U.S. allies of not paying their fair share of defense costs, raising the prospect the U.S. might not come to their aid in the future.

Earlier in the event, Trump adviser and former New York City Mayor Rudy Giuliani also sought to reassure the audience of about 100 people that Trump understands what “his solemn obligation” to NATO would be.

“If you elect Donald Trump, you will find a man who understands that Poland — unlike some of the countries he’s pushing a little for a little money — Poland pays its bills to NATO,” Giuliani said.

Trump’s indignation with some U.S. allies is a regular theme of his stump speeches.

“We defend Japan, we defend Germany, we defend South Korea, we defend Saudi Arabia, we defend countries. They do not pay us. But they should be paying us, because we are providing tremendous service and we’re losing a fortune,” Trump said Monday in his first debate with Democratic opponent Hillary Clinton. “All I said was, they may have to defend themselves or they have to help us out.”