In lobbying for Mr. Trump’s visit in recent months, Polish officials made a promise of a positive reception for the president part of their pitch. Polish Foreign Minister Witold Waszczykowski said in an interview Wednesday with The Wall Street Journal that he told Mr. Trump, on the sidelines of the North Atlantic Treaty Organization summit in Brussels in May: “Please visit us, your soldiers are already here, you can follow, and you can visit a country which is friendly.”

Mr. Trump responded, according to Mr. Waszczykowski, that “Polish Americans helped him win” the presidential election.

“I said, ‘Well, we can help you once again ... if you visit us and cooperate with us,’” Mr. Waszczykowski recalled.