The White House estimates that more than one-thousand North Korean soldiers have been killed or wounded in the last week alone during attacks against the Ukrainian forces.

At an online press briefing on Friday, White House national security spokesperson John Kirby said North Korean forces have been conducting "massed, dismounted assaults" against Ukrainian positions in Russia's Kursk region.

Kirby said such "human wave tactics" were not all that effective, and were resulting in heavy casualties for the North Korean forces.

The U.S. official said it is clear that Russian and North Korean military leaders are treating their troops as expendable and ordering them on hopeless assaults against Ukrainian defenses.

Kirby said the North Korean soldiers appear to be "highly indoctrinated," pushing attacks even when it is clear that they are futile. He also said the soldiers are reportedly taking their own lives rather than surrendering, likely out of fear of reprisals against their families in the North.