The United States has imposed sanctions on a Russian man who it says is the leader of the Wagner mercenary group's operation in Mali.

The US Treasury said Ivan Maslov was a key figure in Wagner's global activities.

It said Wagner may be using its presence in Mali to conceal efforts to acquire military weapons and equipment for the war against Ukraine.

It also accused the Russian group of supplying anti-aircraft missiles to the Rapid Support Forces in Sudan.

Earlier this year, the US designated Wagner as a transnational criminal organisation.

The group has been helping Mali's military government fight Islamist insurgents.

“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 Department said in a statement.