The deal permits Russian private military contractors, the Wagner Group, to operate in the former French colony, the sources said.

A European source who tracks West Africa and a security source in the region said at least 1,000 mercenaries could be involved.

Two other sources believed the number was lower, but did not provide figures.

Four sources said the Wagner Group would be paid about 6 billion CFA francs ($10.8 million) a month for its services. One security source working in the region said the mercenaries would train Malian military and provide protection for senior officials.

The impending deal has angered France, Mali’s former colonialists and are making moves to frustrate it.

France’s diplomatic offensive, the diplomatic sources said, includes enlisting the help of partners including the United States to persuade Mali’s junta not to press ahead with the deal, and sending senior diplomats to Moscow and Mali for talks.

France is worried the arrival of Russian mercenaries would undermine its decade-old counter-terrorism operation against al Qaeda and Islamic State-linked insurgents in the Sahel region of West Africa at a time when it is seeking to draw down its 5,000-strong Barkhane mission to reshape it with more European partners, the diplomatic sources said.

“An intervention by this actor would therefore be incompatible with the efforts carried out by Mali’s Sahelian and international partners engaged in the Coalition for the Sahel for security and development of the region,” the source said.

A spokesperson for the leader of Mali’s junta, which took power in a military coup in August 2020, said he had no information about such a deal.

“These are rumours. Officials don’t comment on rumours,” said the spokesperson, Baba Cisse, who declined further comment.

Mali’s defence ministry spokesperson said: “Public opinion in Mali is in favour of more cooperation with Russia given the ongoing security situation. But no decision (on the nature of that cooperation) has been made.”