Russia, aided by Wagner, has poured massive resources into its military operations in the city despite heavy losses on the ground. And the group continues to recruit new fighters in an effort to expand its forces and operations in the region, the senior U.S. official said, requesting anonymity to discuss sensitive national security matters.

Oleksandr Danylyuk, the former national security adviser for Ukraine who currently advises on military planning, said Kyiv is seeing that expanded footprint in Bakhmut.

“They recently hired a lot of prisoners. They’re being pushed on the frontline [in Bakhmut],” Danylyuk said. “They are — I cannot say fearless — but they have nothing to lose pretty much. So, they are attacking constantly and they’ve been killed in big quantities as well.”

The U.S. said Thursday that North Korea recently sent a new shipment of weapons — rockets and missiles — to Russia for use by Wagner. Wagner paid for the weapons, National Security Council spokesperson John Kirby said in a statement to reporters.

“We assess that the amount of material delivered to Wagner will not change battlefield dynamics in Ukraine, but we are certainly concerned that North Korea is planning to deliver more military equipment,” Kirby said.

Wagner is owned by Russian oligarch Yevgeniy Prigozhin and engages in paramilitary activities across the globe, including in Africa and the Middle East. Its operations in Syria, for example, are wide-ranging. It also engages in social media political misinformation campaigns. The U.S. has sanctioned Prigozhin, Wagner and its network.

Kirby said Russian President Vladimir Putin is “increasingly turning to Wagner for military support.” Wagner is spending more than $100 million per month to fund his group’s operations inside Ukraine, Kirby said.

In his statement Kirby called out Prigozhin for his group’s human rights violations, adding that Wagner has gained independence from Russia’s defense ministry and in some instances “Russian military officials are actually subordinate to Wagner’s command, subordinate to Wagner’s command,” Kirby said.

The Biden administration will now take the step to designate Wagner as a military end user — an action taken by the Department of Commerce to ensure the group cannot access any equipment based on U.S. technology. The administration also plans on announcing additional sanctions against Wagner and those who support the group, Kirby said.