MOSCOW (Reuters) - Russia will send additional military supplies and instructors to Burkina Faso to help the west African country boost its defence capabilities and fight terrorism, Russian state media quoted Foreign Minister Sergei Lavrov as saying on Wednesday.

Burkina Faso, under military leadership since a 2022 coup, has played host to contingents of the Wagner mercenary force, whose founder Yevgeny Prigozhin was killed in a plane crash last August.

"From the very first contacts between our countries after President (Ibrahim) Traoré came to power, we have been very closely engaged in all areas of cooperation, including the development of military and military-technical ties", TASS news agency cited Lavrov as saying during a visit to Burkina Faso.

"I have no doubt that thanks to this cooperation, the remaining pockets of terrorism on the territory of Burkina Faso will be destroyed," he told a press conference in the capital Ouagadougou.

Lavrov has made a series of visits to Africa since the start of the war in Ukraine as Russia, hit by Western sanctions, seeks new trade partners and tries to rally developing countries behind its vision of a "multipolar world" no longer dominated by the United States and former European colonial powers.

Growing Russian security ties with Africa, including countries such as Mali, Burkina Faso and Niger where military leaders have seized power in coups, are a source of concern to the U.S. and other Western governments.

Separately, the RIA news agency reported on Wednesday that Russian aluminium giant Rusal is in negotiations with the government of Sierra Leone on a bauxite mining concession.

Rusal already has operations in neighbouring Guinea.

Sierra Leone's mining minister made the comments on the sidelines of the St Petersburg International Economic Forum.

RIA also reported, without providing details, that Russia's top diamond producer Alrosa was planning talks with Sierra Leone.

(Reporting by Reuters; Writing by Lucy Papachristou; Editing by Mark Trevelyan)