"I don't know how many will come," EU Home Affairs Commissioner Ylva Johansson replied at the special meeting of EU interior ministers in Brussels when asked what influx of refugees from Ukraine she expects. "I think we will have to prepare for millions."

By Sunday, four days after the Russian attack began, at least 200,000 people, mostly children, women and elderly men, had entered Poland, according to the Polish Border Guard. Men considered fit for military service are currently not allowed to leave Ukraine.

Estimates by the United Nations and refugee organizations put the number of people fleeing the Russian invasion at 4 to 7 million. How many will then actually want to cross Ukraine's borders depends entirely on how the military situation in this war develops. Yet how long they want or need to stay depends on who wins or ends this war. If Russia stops its attacks and withdraws, the families could also quickly return to their fathers, sons and brothers, EU officials believe.

Unlimited admission this time

What is clear is that the expected arrivals will far exceed the so-called "refugee summer" of 2015, when about 1 million refugees and asylum-seekers arrived in Central Europe, primarily to Germany, from Syria's war zone.

To date, the EU member states have not been able to find a solidarity-based distribution mechanism for such refugee flows. Legally speaking, the states of first entry are responsible for processing the asylum applications. But countries like Poland, Hungary or Austria in the past have at times refused to accept asylum-seekers at all. Solidarity on the migration issue has been the biggest bone of contention in the EU. But the situation now is completely different.

"It's war in Europe again for the first time, and that is also leading to a different way of thinking among member states," German Interior Minister Nancy Faeser said at a meeting with her European counterparts in Brussels. She sees it as a "total paradigm shift."

All refugees from Ukraine are welcome, European Commission President Ursula von der Leyen promised. "Everyone who has to flee Putin's bombs will be welcomed with open arms."

Initially, many European countries including Germany welcomed refugees in 2015, though the mood changed as the numbers grew.

Accepting refugees from third countries

Now, conditions are different because immediate neighbors are fleeing war; something that Europe no longer thought possible.

The vast majority of people from Ukraine are staying with relatives or friends in Poland, Slovakia, Hungary or Romania. Polish authorities say that special accommodations have hardly been tapped — so far.

There were reports that people from Africa who lived in Ukraine and wanted to enter Poland were harassed or turned away at the border by Polish border guards. A South African Foreign Ministry official tweeted that South African students were turned away at the Ukraine-Poland border, while African embassy staff are working to help compatriots enter the country from Ukraine at Polish border crossings.

In Brussels, Ylva Johansson made it clear that the border was also open to people from third countries who lived in Ukraine and wanted to travel on to their home countries. "Those people must be helped. Moreover, those in need of protection in the EU can also apply for asylum."

No fence in Poland

As yet, there has been no need for an official distribution mechanism for refugees from Ukraine: Poland and Ukraine's other neighboring countries have not yet submitted any requests to resettle anyone, according to the German Interior Ministry.

"Poland is taking in refugees and doing it in an excellent way," Faeser said. "We are now trying to support Poland logistically."

All this sounded quite different a few weeks ago, when Poland began building fortifications on its border with Belarus to keep refugees and asylum-seekers from Iraq and Afghanistan, or other migrants, from entering. The Polish government refused to grant asylum to these refugees, partly because Belarusian leader Alexander Lukashenko was reportedly transporting them to the border deliberately, and then leaving many to hold out in a no man's land for weeks in the cold.

Now things are different. The EU has no problems with those entering from Ukraine, because as a regular rule, Ukrainians can stay in the EU for 90 days without a visa. "But we must be prepared for Day 91," warned Johansson.

That's why, for the first time, the EU will use a "temporary mass protection" law to extend refugees' residency status without having to go through complex asylum procedures. This protection directive, brought in following the wars in the former Yugoslavia in the 1990s, has existed in 2015 but had not yet been applied.

But for Lithuanian Interior Minister Agne Bilotaite, the EU measures agreed on Sunday do not go far enough. She wants a fixed distribution mechanism for refugees from Ukraine, which she thinks the European Commission in Brussels should organize. "You also need a resettlement mechanism to get the wounded, women and children out of Ukraine." She argued that preparations must be made now for the next weeks. Europe's interior ministers will meet again on Thursday.

This article was originally written in German.