US Secretary of Defense Lloyd Austin arrived in the Ukrainian capital, Kiev, on Monday.
According to Reuters, Austin said on his account on the X platform that he arrived in Kiev on Monday for a surprise visit.
He added, "I am here today to deliver an important message that the United States will continue to stand with Ukraine in its fight for freedom against Russia, now and in the future."
According to Voice of America radio, Austin was received at the train station in Kiev by the US Ambassador to Ukraine, Bridget Brink, and the US Defense Attaché, Kipling Kahler, and they were joined on the trip by US General Christopher Cavoli, who serves as NATO's Supreme Commander in Europe.
Senior US defense officials said Austin came to Kiev to discuss Ukraine's winter fighting and plan for future security assistance.