Ukraine’s need for additional air defense systems to protect the country from incoming Russian drones and missiles is exacerbated by the U.S.’s decision to halt some military aid shipments to them.

Ukrainian President Volodymyr Zelensky and President Donald Trump spoke on Friday morning, just days after news emerged that the Department of Defense had paused shipments of U.S. military aid to Ukraine amid concerns about depleted U.S. stockpiles.