Vice President Kamala Harris hailed Poland’s compassion in taking in more than a million migrants since Russia invaded Ukraine last month on Thursday.

Harris made the remarks at a meeting with Polish Prime Minister Mateusz Morawiecki, which came only hours after the US House of Representatives passed a large spending plan that included $13.6 billion in aid for Ukraine and its European allies.

The package contains $6.8 billion for refugee assistance and other economic assistance to partners.

“I’ve been watching or reading about regular individuals doing incredible things, and I’d like to express my gratitude on behalf of the American people,” Harris added.

Harris also met with Polish President Andrzej Duda, and the two were set to conduct a joint press conference later that afternoon. The vice president was scheduled to meet with Ukrainian refugees who have fled to Poland since the Russian assault began later on Thursday.

While in Warsaw, the vice president will meet with Canadian Prime Minister Justin Trudeau. In recent days, the Canadian leader has been in Europe engaging with allies regarding Ukraine.

The White House portrayed Harris’ short trip to Poland and Romania as an opportunity for the vice president to meet with two leaders from NATO’s eastern flank members to discuss the mounting humanitarian situation precipitated by Russia’s invasion of Ukraine.

More than 2 million refugees have already fled Ukraine, with more than half of them arriving in Poland, and more are anticipated to come in the coming days.

However, disagreements between Warsaw and Washington over a Polish proposal to transport Soviet-made fighter planes to a German base for use by Ukraine have placed a pall on Harris’ trip to Poland. The Pentagon flatly rejected the plan just before Harris landed in Warsaw late Wednesday evening.

Poland presented the idea without consulting the US, only days after Secretary of State Antony Blinken claimed the Biden administration was “very, very aggressively” considering a proposal in which Ukraine’s neighbor Poland would supply Kyiv with Soviet-era fighters in exchange for American F-16s.

Officials from the Polish administration, on the other hand, urged that any plane transfers take place inside the NATO framework.

On Wednesday, the Pentagon ruled out the possibility of NATO deploying fighter planes to Ukraine, claiming that such a move by the US and NATO would have a “high danger” of worsening the Russia-Ukraine conflict.

The head of US European Command, Gen. Tod D. Wolters, said in a statement on Thursday that providing increasing numbers of anti-tank weaponry and air defense systems is the “most effective method to help the Ukrainian military in their struggle against Russia.” According to Wolters, the US and its allies are continuing their efforts.

On Friday, Harris will go to Bucharest to meet with Romanian President Klaus Iohannis.