Live updates: As many as 15,000 Russians killed in fighting

The battlegroups, which usually number between 1,000-1,500 troops, will be set up in Hungary, Slovakia, Romania and Bulgaria. Stoltenberg says they will remain in place “as long as necessary.”

Speaking Wednesday on the eve of a summit of NATO leaders, Stoltenberg said that Russia’s war on Ukraine means “a new normal for our security and NATO has to respond to that new reality.”

Stoltenberg says the leaders are likely to agree to send more assistance to Ukraine, including “equipment to help Ukraine protect against chemical, biological, radiological and nuclear threats.”

NATO’s 30 allies are worried about Russian rhetoric and fears that Moscow might want to create a pretext to use chemical weapons in Ukraine.

Stoltenberg says that “any use of chemical weapons would totally change the nature of the conflict,” and would have “far-reaching consequences” for Russia. He declined to elaborate.

PRZEMYSL, Poland — Ukrainian refugees continued to arrive at the train station in the border city of Przemysl, Poland, on Wednesday.

Kateryna Mytkevich, 39, arrived from Chernihiv in northern Ukraine.

“We endured (the fighting), trapped at home for three weeks,” Mytkevich said. “We hoped the war would pass us by. But then the heavy artillery shifted to our city and bombs began to fall. Two schools in the city center were blown up, there were small children there. It’s so difficult. I don’t understand why we have such a curse.”