flank. president biden came within 50 miles of the ukrainian border today and said he wished he could get closer. >> thank you very, very much for all you do. >> reporter: he stopped in rzeszow, poland to share a slice with members of the 82nd airborne who are part of the massive aid effort in this town that has now become a processing points for tens of thousands of ukrainian refugees. >> we sent the best, the best available in america, and that's all of you. >> reporter: 3.7 million people have fled ukraine in the past month. more than half of them have come here to poland. today, the polish president referred to them as guests. president biden called vladimir putin a war criminal, intent on causing civilian suffering. >> he's not stopping. it's like something out of a science fiction movie. you turn on the television, and see what these towns look like. >> reporter: president biden flew to poland from brussels, where earlier today, he