"The aim of the visit is to express the European Union's unequivocal support for Ukraine and its freedom and independence," Czech Prime Minister Petr Fiala announced on Twitter. And Poland's Mateusz Morawiecki said in a social media post that the visit will happen on the 20th day of Vladimir Putin's "criminal aggression against Ukraine."

"At such breakthrough times for the world, it is our duty to be where history is forged. Because it's not about us, but about the future of our children who deserve to live in a world free from tyranny," the Polish prime minister said. "The aim of this visit is also to present a broad package of support for Ukraine and Ukrainians."

Reuters notes that "The Czech Republic and Poland, former communist members of both the EU and NATO, have been among the strongest backers of Ukraine in Europe since the Russian invasion."

Traveling in the group includes: Poland's Prime Minister Mateusz Morawiecki and Deputy Prime Minister Jaros?aw Kaczy?ski, as well as Czech Prime Minister Petr Fiala and Prime Minister of Slovenia Janez Janša.

While all three countries are said to be absorbing refugees, Poland - which shares a large border with Ukraine - is seeing by far the most, with an estimated more than 1.7 million refugees entering the country since Russia's Feb.24 invasion.

Two large Polish cities have recently warned they have reached "capacity" as refugees pour in - and there's not enough infrastructure or housing to support them, as The Guardian describes:

Ossoli?ska said many people working on the ground were now struggling to find places to accommodate everyone. "From day to day, it is much harder to find a private place for refugees."