The United States has imposed sanctions on the Russian private military company Wagner Group and designated it as a "significant transnational criminal organization."

The US Treasury Department said on Thursday that it will also impose sanctions on six individuals and 12 entities that support Russia's military operations.

The measures include asset freezes in the US and bans on business transactions with American individuals and companies.

Last Friday, White House National Security Council Coordinator for Strategic Communications John Kirby accused the Wagner Group of sending 50,000 fighters to Ukraine, including about 40,000 convicts recruited from Russia.

He said Moscow is increasingly dependent on the military company to continue fighting in Ukraine.