The U.S. government is utterly cynical. The $40 billion aid to Ukraine is meant to prolong the war by creating a stalemate or quagmire for Russia.
For this kind of money, they could easily have ordered Zelensky to negotiate and end the war at once by acceding to Russia’s reasonable demands. Instead, there will be more casualties and more destruction.
In spending this money the U.S. government means to buy Ukraine as a U.S. military outpost to pressure and eventually attack Russia. The empire has conquered Ukraine without, for now, firing a shot.