The head of Russia's private military contractor, the Wagner Group, reportedly sent a letter to the White House, seeking clarification on what crime the group was accused of after Washington announced new sanctions on them.

According to Reuters, Wagner founder Yevgeny Prigozhin sent a short letter to White House National Security Council spokesperson John Kirby on Saturday, asking “Dear Mr Kirby, could you please clarify what crime was committed by PMC Wagner?”

The letter comes a day after Kirby announced new sanctions against the group and designated it as a significant transnational criminal organization, revealing new imagery indicating North Korea supplied arms to the group.

Kirby said that the arms transfer is in direct violation of United Nations Security Council resolutions.

Last month, the White House said that North Korea sold ammunitions, rockets and missiles to the Wagner Group in violation of UN Security Council resolutions. North Korea has flatly denied the allegations.