President Joe Biden appeared to reveal that the U.S. is training Ukrainian forces in Poland -- stating for the first time since the war began that American troops are actively teaching Ukrainians to fight and kill Russians.

The United States has been providing billions of dollars in weapons and other assistance to Ukraine, with much of that aid going through Poland. The president spent part of last week in the country, meeting with U.S. troops stationed in the southeast and delivering a speech about the West's unity in the face of Russian aggression.