The Biden administration on Friday upgraded its classification of Russia's Wagner Group to a “significant transnational criminal organisation” and announced coming sanctions against the private military group.
White House National Security Council spokesman John Kirby told reporters that the new designation would “put more squeeze” on Wagner's ability to do business around the world and will “broaden the network” of nations and institutions that will stop doing business with the group.
“We will work relentlessly to identify disrupt, expose and target those who are assisting Wagner,” said Mr Kirby.
He added that new sanctions against the group will be announced next week.
The White House also released newly declassified images that apparently show a weapons delivery from North Korea to Wagner, in an attempt to counter Pyongyang's denial of the delivery.
Russia and North Korea share a 17-kilometre land border and the two countries have a connecting train line.
The White House announcement came after a defence leaders meeting at the US Ramstein airbase in Germany on Friday failed to resolve divisions over providing advanced battle tanks to Ukraine.
Wagner last week said it had taken control of the strategic town Soledar, though Kyiv denied those claims.
Mr Kirby also said that there is “likely mounting tension” between Russian officials and Wagner's leader Yevgeny Prigozhin, after the White House warned last month that in some instances, Moscow's military forces are “actually subordinate” to Wagner's command.
The upgraded designation is the Biden administration's second in less than a month, though it has not officially designated the group as a terrorist organisation.
A bipartisan group of US senators introduced the Holding Accountable Russian Mercenaries (Harm) Act in December that would require the designation of Wagner Group as a foreign terrorist organisation.
“[Russian President Vladimir] Putin and his cronies will stop at nothing to accomplish their objectives, including employing mercenaries like the Wagner Group to commit atrocities on their behalf,” Senator Roger Wicker, who introduced the bill, said in a statement.