WATCH: Airstrike on training base used by NATO is “broadening” of Ukrainian targets by Russians, says Pentagon

A Russian airstrike on a military base that had been used for training exercises between Ukraine and NATO represents an expansion of potential targets in that country, Pentagon spokesman John Kirby said on Monday.

Watch Kirby’s remarks in the player above.

“We know that several structures were hit. We don’t’ have a perfect picture of what damage was done or how much gear and equipment was hit,” Kirby told reporters during a press briefing. “This is now the third significant strike in western Ukraine. It certainly appears the Russians are broadening their target set.”

The attack killed 35 people, Ukrainian officials said, and raised fears that NATO could be drawn into direct conflict with Russia. It also shook the confidence of Poland, whose border with Ukraine was only 15 miles away. On Monday, nine people were killed in a morning rocket attack on a television tower in Antopol, about 100 miles (160 kilometers) from the Polish border.

Polish Prime Minister Mateusz Morawiecki said the attack, close to a refugee route to Poland, was also intended to “provoke panic among civilians” fleeing the “horrors of the war.”

Kirby said that no U.S. military or officials were killed in the attack. He said it would not affect military aid being sent to the Ukrainian government.

“We have multiple routes to get security assistance into the hands of Ukrainians. This was not one of them,” Kirby said.