The United States has rejected Poland’s offer to send its MiG-29 fighter jets to Ukraine via a US airbase in Germany, saying the proposal raised “serious concerns” for the entire NATO alliance, writes Al JAzeera.

Warsaw made the surprise offer on Tuesday amid repeated appeals from Ukraine’s President Volodymyr Zelenskyy for more warplanes to replenish his country’s air force as it defends against invading Russian forces.

The Polish scheme proposed that the Russian made MiG-29 fighter jets be delivered to a US base in Ramstein, Germany, and then be deployed to Ukraine.

But Pentagon spokesman John Kirby said the prospect of the jets flying from a US-NATO base “into airspace that is contested with Russia over Ukraine raises serious concerns for the entire NATO alliance”.

“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. It is simply not clear to us that there is a substantive rationale for it”, - Kirby said in a statement.