WATCH: Pentagon says Russia has continued bombardment of Mariupol steel mill

Russia resumed pulverizing the Mariupol steel mill that has become the last stronghold of resistance in the bombed-out city, Ukrainian fighters said Monday, after a brief cease-fire over the weekend allowed the first evacuation of civilians from the plant.

Watch Kirby’s remarks in the player above.

More than 100 people – including elderly women and mothers with small children – left the rubble-strewn Azovstal steelworks on Sunday and set out in buses and ambulances for the Ukrainian-controlled city of Zaporizhzhia, about 140 miles to the northwest, according to authorities.

“We do assess that the Russians continue to pound Mariupol from the air,” said Pentagon Spokesman John Kirby.

“We have seen some indications that they are moving some of their ground forces away from Mariupol,” he said. “The the general consensus here is that that’s an effort to begin to move north into the Donbas.”

The Russian military says just under 70 people who came out of the plant on Sunday chose to be evacuated to Ukraine-controlled territories, while just under 60 from the plant and surrounding areas asked to stay in the areas under Russian control.

The Ukrainian authorities have not yet confirmed this data, and it could not be independently verified.

Kirby said that most of the 90 Howitzers committed by the U.S. to Ukraine is now in the country.

He said no one knows how long Russia’s invasion of Ukraine will last.

“I’ll keep saying it every day. It could end today. It could end right now,” he said.

“This is a war of choice that Mr. Putin decided to wage on his own while he still had diplomatic options on the table. So it could end now, there’s no reason for it to go a single other day.”

Analysts wonder if pushing to arm Ukraine putting strain on US weapons stockpiles.

The U.S. already provided about 7,000 Javelins, including some that were delivered during the Trump administration, about one-third of its stockpile, to Ukraine, according to one analysis. The Biden administration says it has given about 5,500 to Ukraine since the Russian invasion more than two months ago.

Kirby said the delivery of weapons is not affecting the Defense Department’s readiness to defend the U.S.

“With every drawdown package, we make an assessment about the impact on our readiness. And what I can tell you is that thus far we have not seen any negative impact on our ability to defend this nation across a range of military capabilities,” he said.

“But that is not something we take lightly,” he said.