The United States is not “hand-wringing” over the mass casualties of Russian soldiers in a Ukrainian attack reportedly using US-supplied artillery, a senior White House official said Wednesday.

After criticism in Russia over the use of US-delivered weaponry by Ukrainian defenders, including in the Makiivka strike, national security council spokesperson John Kirby said Russia is to blame.

There is no “hand-wringing by the administration at all. This is a war. They have been invaded and they (Ukrainians) are striking back and defending themselves,” Kirby said. “Russian soldiers in their territory are legitimate targets for Ukrainian military action, period.”

Kirby would not give a US estimate of the casualties in an attack that all sides agree was unusually fatal, even by the bloody standards of the now more than 10-month-old Russian invasion.

“I’m not going to get into the casualty count. It is war. And it is in a vicious area of fighting right now. And war is a bloody affair,” he said.