That apparently was not US govt proposal though? It was at first mentioned as idea by Josep Borell and was about all postsocialist countries still having soviet planes, and then it was repeated by Zelensky. The polish command responded there is no such proposal and denied there is anything in it. Then PM Morawiecki said Poland will not pass the planes to Ukraine since they are not part of the war, but to the US, for which Pentagon replied it won’t be possible. They later asked Nuland about that and she said it was polish proposal.