WASHINGTON - The US on Thursday said Russian mercenary force Wagner Group may be working through Mali and other countries to hide its efforts to acquire military equipment for use in Ukraine, and accused it of supplying a Sudanese paramilitary with surface-to-air missiles.

The US Treasury Department said in a statement it imposed sanctions on Wagner’s chief in Mali as it said the group’s employees may have been attempting to work through the west African country to acquire equipment such as mines, drones, radar and counterbattery systems for use in Ukraine.

The US has repeatedly warned of what it says are Wagner’s destabilising activities and has ramped up sanctions against the private army following Russia’s invasion of Ukraine last year. Wagner mercenaries have fought alongside regular Russian troops in Ukraine, including in some of the most intense battles.

On Monday, State Department spokesman Matthew Miller warned that Wagner was seeking to transit military equipment through Mali. Ms Maria Zakharova, spokeswoman for Russia’s foreign ministry, on Wednesday dismissed the US allegations as a “hoax.”

“Treasury’s sanctions against the most senior Wagner Group representative in Mali identify and disrupt a key operative supporting the group’s global activities,” the Treasury’s Under Secretary for Terrorism and Financial Intelligence, Mr Brian Nelson, said in the statement.

“The Wagner Group’s presence on the African continent is a destabilising force for any country that allows for the deployment of the group’s resources into their sovereign territory.”

The Treasury accused Wagner of supplying Sudan’s Rapid Support Forces (RSF) with surface-to-air missiles, which could give the paramilitary group a boost in the fighting against the Sudanese army, which is heavily reliant on air strikes to target the RSF.

Fighting between the two parties that broke out last month has worsened a humanitarian crisis, forced more than 1.3 million people to flee and threatened to destabilise a fragile region.

The head of the RSF, Mohamed Hamdan Dagalo, also known as Hemedti, has culti...