The US will withdraw more than 1,000 military personnel from Niger in a move that will force the Biden administration to rethink its counter-terrorism strategy and amounts to a strategic victory for Russia.

The decision comes a month after the west African country’s ruling military junta revoked a security pact with Washington that had allowed American forces on its soil to help fight jihadist terrorism.

US officials had voiced hopes that behind-the-scenes talks could salvage the 12-year-old agreement, which was thrown into jeopardy on 15 March when a junta spokesperson publicly declared the continued US military presence in Niger “illegal”.

But the US finally admitted defeat after meetings in Washington this week between Kurt Campbell, the deputy secretary of state, and Niger’s prime minister, Ali Lamine Zeine.

The withdrawal, expected to occur over the coming months, will mean the closure of a US drone facility, known as Base 201, at Agadez in the Sahara that was opened in 2018 at a cost of $110m.

The base, one of the main US drone facilities in Africa, has been used in operations against jihadist groups in the Sahel region and was reportedly the launchpad for a series of deadly strikes against Islamic State fighters in Libya in 2019.

Niger’s relations with Washington have been tense since last July when the democratically elected president, Mohamed Bazoum, was overthrown in a coup. He remains under house arrest, despite American calls for his release.

Since the coup, Niger’s new leaders have pursued closer ties with Russia, mirroring neighbouring Mali and Burkina Faso, where Russian military forces have established a presence.

Just days after the arrival of Russian military equipment and advisers in the country, thousands of protesters gathered in the Nigerien capital, Niamey, last week to demand the withdrawal of American forces.

According to Russian reports, the newly arrived personnel were part of Russia’s Africa Corps, a new paramilitary group established to replace the Wagner Group, the mercenary outfit founded by Yevgeny Prigozhin.

Prigozhin had been an ally of Vladimir Putin until he led a failed rebellion last year against the Russian president’s stewardship of the war in Ukraine; he was killed in a plane crash. He offered the Wagner Group’s services to the coup leaders after they seized power.

US military commanders have warned of the spread of Russian influence in the Sahel, a semi-arid region in the southern Sahara stretching from the Atlantic to the Red Sea, and in other parts of Africa at American expense.

American alarm rose when Lamine Zeine visited Moscow last December to discuss military and economic ties, followed by a visit to Tehran the following month, where he met Ebrahim Raisi, the Iranian president.

Senior state department and Pentagon officials visited Niger earlier this year in an effort to keep the military agreement intact.

The visit was not a success, with Nigerien figures voicing anger over what they said were unfounded American suspicions of negotiations to allow Iran access to Niger’s uranium resources, potentially enhancing Tehran’s nuclear programme.

The departure of American forces from Niger follows the expulsion of French troops after last summer’s coup.