FILE - Secretary of the Army Christine Wormuth looks over the latest version of the M1A2 Abrams main battle tank as she tours the Joint Systems Manufacturing Center, Feb. 16, 2023, in Lima, Ohio. Two U.S. officials say Ukraine has sidelined U.S.-provided Abrams M1A1 battle tanks for now in its fight against Russia. This is in part because Russian drone warfare has made it too difficult for them to operate without detection or coming under attack. (AP Photo/Carlos Osorio, File)