Russian military instructors have arrived in Niger with an air defence system and other equipment as part of the West African nation's deepening security ties with Moscow, state television announced late on Thursday.

Niger's military government agreed in January to step up security cooperation with Russia, after expelling French forces that were helping fight jihadist rebellions in several Sahel nations.

On Friday, African Corps -- seen as the successor of Russia's Wagner mercenary group in Africa -- confirmed it had arrived in Niger.

The Tele Sahel broadcaster showed a Russian transport plane arriving at Niamey airport on Wednesday night.

It said "the latest military equipment and military instructors from the Russian defence ministry" had arrived.

Russia will help "install an air defence system... to ensure complete control of our airspace", the report said.

One instructor was quoted as saying that "We are here to train the Niger army and help it use the equipment that has just arrived. The equipment is for different military specialities."

"The first flight of African Corps troops and volunteers has arrived in Niger," the group wrote on Telegram.

The Wagner mercenary group had unofficially served the Kremlin's aims in Africa since the 2010s.

Rebranded African Corps and reorganised following the August 2023 death of its founder Yevgeny Prigozhin in a mysterious plane crash, the group is now under the Kremlin's umbrella, signalling a formal acknowledgement of Russia's role in the Sahel.

The head of Niger's military government, General Abdourahamane Tiani, spoke by telephone with Russian President Vladimir Putin on March 26.

The two leaders discussed security cooperation as well as "global strategic cooperation" against "current threats", authorities said at the time, without elaborating.

Niger, one of the world's poorest countries, had been a frontline partner of the West in battling jihadists in the Sahel but has turned to Russia since the elected president was ousted last July.

Niger has also joined neighbours Mali and Burkina Faso -- also ruled by military leaders after coups -- to create a joint force to battle long-running jihadist insurgencies.

The junta kicked out forces from former colonial power France, whose 1,500 troops had left Niger by the end of last year.

The military also announced it was breaking off a 2012 agreement with the United States, which has built a desert drone base at a cost of $100 million in northern Niger and has some 1,000 troops in the country.