A senior US delegation has left Niger after a three-day visit to renew contact with a junta that ousted the West African country's elected president and moved closer to Russia.

"The American delegation left Niamey on Thursday after meeting several Nigerien officials, including Prime Minister Ali Mahaman Lamime Zeine," a diplomatic source said.

The delegation, led by Assistant Secretary of State for African Affairs Molly Phee, was initially due to have stayed in Niamey for two days but then extended the visit by a day, a Nigerien government source said.

The team members however could could not meet junta leader Abdourahamane Tiani as planned initially, according to a programme put out by the Americans.

General Michael Langley, the commander of US Africa Command, was part of the delegation.

The United States still stations some 1,000 troops in Niger at a desert drone base built at a cost of $100 million -- although movements have been limited since the coup and Washington has curbed assistance to the government.

Secretary of State Antony Blinken paid a rare visit to Niger a year ago in hopes of shoring up Mohamed Bazoum, the elected president and stalwart ally in Western security efforts against jihadists.

Just four months later, the military deposed Bazoum and put him under house arrest.

The junta took a hard line against former colonial power France, forcing the withdrawal of French troops in place for nearly a decade.

Niger's military, which has worked closely with the United States, has not demanded a similar pullout of US forces.

But the junta has sought cooperation with Russia, while stopping short of the full-fledged embrace of Moscow by military-run neighbours Mali and Burkina Faso.