Russia has suffered more than 100,000 casualties since December fighting in the eastern Ukrainian city of Bakhmut, a White House official said Monday.

National Security Council spokesman John Kirby told reporters the figure includes about 20,000 soldiers killed in combat and 80,000 wounded.

Kirby said the numbers are based on “information and intelligence that we were able to corroborate over a period of of some time.”

While fighting in Bakhmut preceded December, Russia launched a broad offensive then that included Bakhmut, Vuhledar, Avdiivka and Kreminna, located in the provinces of Donetsk and Luhansk. 

“Most of these efforts have stalled and failed,” Kirby said. “Russia has been unable to seize any real strategically significant territory. 

“The only area where Russia has made some incremental gains — and I want to focus on the word ‘incremental’ — is Bakhmut,” he added. “That really holds, as we've said before, very little strategic value for Russia. The capture of Bakhmut would absolutely not alter the course of the war in Russia's favor, and Ukraine's defenses in the areas surrounding Bakhmut still remain strong.”

About half of the 20,000 Russian fighters killed in the war were from the Russian mercenary Wagner Group, most of whom were recruited out of prisons, Kirby said.

“Folks he [Wagner Group founder Yevgeny Prigozhin] went knocking around on the doors in prison cells throughout Russia to throw human flesh at this fight,” Kirby said.

The White House compared the Russian casualty toll to a pair of key battles in World War II. It is more than the 19,000 U.S. troops killed and 80,000 wounded in the Battle of the Bulge, and it’s about three times the 7,100 soldiers the U.S. lost in the Battle of Guadalcanal.

Kirby declined to release the number of casualties Ukraine has suffered in the region, saying that disclosing that information is up to Kyiv.

“I'm not ever going to put anything out in the public domain that's going to make their job harder,” he said. “They are the victims here. Russia is the aggressor.”

Kirby said the U.S. is continuing to support Ukraine, including by training battalions outside the country, and added that another aid package will be announced “in the coming days and weeks.”