I didn't say anything about Russia. Don't change the subject.

A report released in January by the Pentagon Inspector General’s office found that the Defense Department failed to conduct proper end-use oversight on more than $1 billion worth of military equipment — nearly forty thousand weapons — sent to Ukraine.

https://jacobin.com/2024/03/ukraine-us-weapons-defense-department

Much more likely its regular old US military corruption or weapon manufacturer corruption along with smuggling on the border.

It may be the USA sending the weapons, but its with the backing of Ukraine's EU neighbors, part of NATO, who completely support them.