Vice President Harris is heading to Warsaw on Wednesday for a trip meant to show unity with Poland and Romania, two U.S. allies that flank Ukraine.
But the visit comes a day after an unusually public disagreement over a Polish proposal to share its fighter jets with Ukraine — an idea that the Pentagon rejected.
Senior administration officials who briefed reporters ahead of Harris' trip downplayed the dispute, saying that there were "a lot of ideas worth discussing" even though this one was judged "not tenable" by the Pentagon, and noting that talks would continue while Harris was overseas.
Ukrainian President Volodymyr Zelenskyy asked U.S lawmakers on Saturday for help getting more Russian-made MiG fighter jets to his military — jets that his pilots know to how to fly.
The White House said it would try to work to help Ukraine get them from Poland — replacing the jets with U.S.-made aircraft for Poland — but said it would be hard to transfer planes into Ukraine.
Then on Tuesday, Poland announced it would send its jets to the U.S. air base at Ramstein, Germany. That caught U.S. officials off guard. Later in the day, the Pentagon issued a statement saying flying planes from a U.S./NATO base in Germany into contested airspace wouldn't work.
"It is simply not clear to us that there is a substantive rationale for it," Pentagon spokesman John Kirby said. "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."
Harris' trip was planned well before the disagreement happened. She has been meeting and talking with NATO allies in Eastern Europe even before Russia invaded Ukraine, and plans to discuss "next steps" to respond to Russian aggression, officials told reporters.
On Thursday, she will hold meetings with Polish President Andrzej Duda and Prime Minister Mateusz Morawiecki — as well as with Canadian Prime Minister Justin Trudeau, who happens to be visiting Warsaw at the same time.
Officials said Harris will meet Ukrainians who have fled their country, as well as U.S. Embassy staff from Kyiv, who are now based in Poland.
Harris will meet U.S. service members stationed in Poland on Friday before she heads to Bucharest to meet Romanian President Klaus Iohannis.
The United States has boosted its troop presence in Poland and Romania to reinforce NATO allies. Harris wants to talk about how the U.S. can provide support for refugees. More than half of the 2 million people who have fled Ukraine are in Poland.