The US Department of Defense has about $4B in presidential funds, allowing it to use its strategic reserves to send military equipment to Ukraine.
However, withdrawing this stock could affect US defense capabilities, and the Pentagon is reluctant to commit these assets without confidence that Congress will replace them as part of a $60B funding package. Pentagon leadership is trying to determine whether there is any internal financial option that would allow at least part of this $4B to be spent on aid to Ukraine.
According to Politico, discussions of this and other options have become increasingly urgent in the past few weeks as the situation on the battlefield in Ukraine becomes increasingly difficult. However, officials emphasize that decisions have yet to be made.