Lech Walesa, the former Polish president and Solidarity trade union leader who played a leading role in the fall of Communism, signed a letter to President Donald Trump expressing "horror" at his argument with Ukraine's Volodymyr Zelenskyy.
The Nobel Peace Prize-winner posted the text of the letter, which was signed by 39 Polish former political prisoners, on Facebook on Monday.
In an extraordinary meeting that was broadcast live on Friday, Trump accused Zelenskyy of being ungrateful for U.S. aid, of showing disrespect to his country and of risking World War III, casting into doubt Washington's ongoing support for Ukraine in its three-year-long war with Russia.