Malcolm Chalmers, deputy director-general of the Royal United Services Institute military think tank, told CBS News in March that about 20% of Ukraine's military hardware is supplied by the U.S., with 25% provided by Europe and the rest of the world, and 55% produced in Ukraine.

The Trump administration is pausing some weapons shipments to Ukraine, including air defense missiles, following a review of military spending and American support to foreign countries, a senior White House official told CNN.