On Monday, the Pentagon downplayed the chances of Poland sending Ukraine Russian-made MiG-29 fighter jets after Secretary of State Antony Blinken said such a plan would get a "green light" from the US.

Blinken said that the US was in discussions with Poland to replenish Warsaw's fleet with US-made jets if it transfers the MiG-29s to Ukraine. But as recently as Sunday, Polish officials have characterized the idea of Poland sending warplanes to Ukraine as "fake news."

When asked about the comments from Polish officials, Pentagon spokesman John Kirby said, "no decisions have been made," and that the decision was ultimately up to Poland.

"This will be a sovereign decision for a nation-state to make. Whether it's Poland or anybody else, that should they want to provide aircraft to the Ukrainian Air Force, that's a sovereign decision that they can make," he said. Kirby stressed that discussions with Poland about the plan are in "very early" stages.