NATO warns of 'high price' if Russia attacks Ukraine

STOLTENBERG: "There will be a high price to pay for Russia if they once again use force against the independent sovereign nation of Ukraine."

BLINKEN: "Any renewed aggression would trigger serious consequences."

That’s NATO Secretary-General Jens Stoltenberg and U.S. Secretary of State Antony Blinken, speaking at the NATO alliance summit in Latvia Tuesday, warning Russia would pay a high price for any new military aggression against Ukraine.

That same day, speaking at an investment forum in Moscow, Russian President Vladimir Putin said his country will be forced to act if NATO deploys certain missiles into Ukraine, which he calls a red line.

But on the frontline of the conflict in Ukraine, in ruins of European neighborhoods smashed by artillery fire, and in towns near an active war zone between the government and pro-Russian separatists, some residents talking to Reuters say they've resigned themselves to the idea that a wider conflict between Ukraine and Russia could come at any time.

This is the town of Kramatorsk, Ukraine, where 34-year-old Roman Balaboiko lives.

He's a veteran of the war against the separatists, a volunteer in a helicopter squadron evacuating wounded troops.

He says he keeps a bag ready in case of a new offensive.

BALABOIKO: "For people in the United States, and in Europe as well, and even for some people in our country it may feel a bit scary. And because of that, people start speculating and wondering, people start fantasizing even more over whether it will happen or not, and how."

"Yes, it's a fact Russia is amassing troops at the border with Ukraine, but I'll say it again: We here in Donetsk and the Luhansk region have got used to the idea that if a large-scale attack happens, we'll be the first to feel it and realize it. I think people here are tired of being afraid."

Kramatorsk is about 30 miles away from the actual front line, where Ukrainian soldiers and residents have told us that the separatists launch artillery strikes every day, trying to provoke a response.

And Moscow dismisses Western concerns of an intervention by Russian troops as alarmist.

It also denies being a party to the separatist movement, though Reuters has previously gathered evidence that Russian troops and weapons have been involved.

On the other side of the front is the town of Horlivka, now held by separatists. Aleksander Studenikin and his wife, Irina, are literally living in the basement of a destroyed school building. Their house was destroyed years ago.

STUDENIKIN: "Believe it or not, all I want is for them to stop shelling. I could agree to that now. But they won't stop. It's to their benefit to keep the fighting going."