GEOFF BENNETT: NATO described it today as a grinding war of attrition, the fight over Eastern Ukraine, where Russian forces have launched operations in multiple areas, and today said they have made incremental gains in Ukraine's Donbass.

That is where Nick Schifrin is again tonight.

His reporting in Ukraine is supported by the Pulitzer Center.

So, Nick, what is Russia claiming today?

And how is NATO responding?

NICK SCHIFRIN: Well, the U.S. believes that the Russian offensive here in the Donbass has begun, focused on two points here in Donetsk province, and an additional point in neighboring Luhansk province.

Russian forces are pushing in the town of Kreminna.

Now, Russia today claimed some kind of incremental progress, but provided absolutely no detail.

But in Luhansk, we have seen Russian tactics, including this village completely wiped out in a video shared by a Ukrainian official.

And you really see, Geoff, old tactics being used, artillery en masse against a single target.

Now, Russia and Ukraine have used millions of rounds of artillery.

And that has meant that the West has had to step up its artillery production And, today, NATO Secretary-General Jens Stoltenberg said that the West wasn't keeping pace enough.

JENS STOLTENBERG, NATO Secretary-General: There's a big need out there to provide Ukraine with ammunition.

This is now becoming a grinding war of attrition.

And the war of attrition is a war of logistics.

And, therefore, this is so crucial for our ability to ensure that Ukraine wins, is able to retake territory.

NICK SCHIFRIN: To give you some perspective, Ukraine fires the number of artillery shells every month that the U.S. produces every year.

Now, the U.S. is increasing its production, but it simply isn't enough, even that increased rate, to match the rate that Ukraine has been firing artillery shells, Mark Cancian of the Center for Strategic and International Studies told me earlier.

MARK CANCIAN, Center for Strategic and International Studies: It's an awful lot of ammunition, but that's only enough for about half of Ukraine's usage.

So Ukraine is going to not have as much ammunition as they would like.

What it means is that the flow of ammunition will slow down, and they will have to prioritize their targets.

They will have to shoot at the most high-priority targets.

And other targets, they will have to let go.

NICK SCHIFRIN: The U.S. is trying to train Ukraine to use less artillery and use more modern tactics, Geoff, and the U.S. hopes that that will pay off in the coming spring offensive.

GEOFF BENNETT: And, Nick, you have been out on the front lines.

Have you seen these new tactics yet?

NICK SCHIFRIN: Yes, it's a little too early, because that training isn't complete.

And there are hundreds of armored vehicles on their way that U.S. and European officials have said should arrive in the next few weeks ahead of that spring offensive.

But we have been on the front lines with drone pilots.

And this is an example of Ukraine modernizing its own infantry, integrating drone pilots into that infantry, having them relay the positions of Russian vehicles in real time to their commanders, who then relay it to artillery to try and fire on those Russian vehicles.

And so we will have that story focusing on drones and the air war certainly in the days ahead of the one-year of full-scale invasion last February.

GEOFF BENNETT: And, of course, as this battle rages, the population of Eastern Ukraine suffers.

What have civilians been telling you, Nick?

NICK SCHIFRIN: Yes, Geoff, they are suffering, and yet, at the same time, they're resilient.

But I met a man a few hours ago who had to watch his own apartment being bulldozed after it had been struck by a Russian missile in a town just a couple of hours from here.

The humanitarian catastrophe here is immense.

The U.N. today appealed for $5.6 billion.

That is one of the largest ever humanitarian appeals, both for internally displaced Ukrainians, as well as refugees.

And they have suffered so much since the invasion last year.

And we will certainly be covering that, Geoff, ahead of next week's invasion, as well -- as well as Ukraine's attempts to reconstruct the country and those front-line reports as well.

GEOFF BENNETT: Nick Schifrin reporting for us tonight from Eastern Ukraine.

Nick, thank you.

NICK SCHIFRIN: Thanks, Geoff.