The Pentagon has rejected Poland's offer to send its MiG-29 fighter jets to Ukraine via a US air base in Germany.
Poland's offer would have had Soviet-era MiG-29 fighters sent to the US base in Ramstein, Germany, with the planes eventually being given to Ukraine. Poland's air force would have then received F-16 fighters as replacements.
"We will continue to consult with Poland and our other NATO allies about this issue and the difficult logistical challenges it presents, but we do not believe Poland's proposal is a tenable one," Pentagon spokesman John Kirby said.
Kirby said flying from a US base "into airspace that is contested with Russia over Ukraine raises serious concerns for the entire NATO alliance."