President Volodymyr Zelenskiy said on Monday that Ukraine had to engage in "substantive" diplomacy to bring to a rapid end the three-year-old war with Russia, and he hoped to be able to rely on U.S. support in securing peace.

U.S. critics of the Ukrainian leader criticized the military garb he wore to the Oval Office as signifying a lack of respect. Ukrainians say it has to do with the war they are fighting.