U.S. Secretary of Defense Lloyd Austin announced $100 million in new military aid to Ukraine during his visit to Kyiv on Monday, pledging long-term American support amid growing concerns about the sustainability of vital U.S. assistance.

Austin announced the aid package after a day of meetings with Ukrainian officials, with the latest tranche including arms such as anti-tank weapons, air-defense interceptors and an additional High Mobility Artillery Rocket System (HIMARS).