U.S. Secretary of State Antony Blinken (L) and U.S. Defense Secretary Lloyd Austin in Washington, DC, on April 11, 2022. NBC News reports Blinken and Austin slipped into Ukraine on Sunday for an extraordinary wartime meeting with President Volodymyr Zelenskyy, bringing new promises of military and diplomatic support.

Secretary of State Antony Blinken and Secretary of Defense Lloyd Austin slipped into Ukraine on Sunday for an extraordinary wartime meeting with President Volodymyr Zelenskyy, bringing new promises of military and diplomatic support and defying grave concerns about whether it was safe to make the journey.

The trip, the highest-level American visit since Russia invaded Ukraine on Feb. 24, was designed to show steadfast U.S. support for Ukraine and its defense, as the war enters a new, worrying phase expected to be marked by a major Russian offensive in Ukraine's south and east.