Biden says he has 'flat assurance' that Ukraine won't use F-16s to go into Russia

U.S. President Joe Biden on Sunday said he had received a "flat assurance" from Ukrainian President Volodymyr Zelenskiy that he would not use Western-provided F-16 fighter jets to go into Russian territory.

Biden told reporters that F-16 warplanes could, however, be used "wherever Russian troops are within Ukraine and the area."