The United States is planning to temporarily withdraw some of its troops from Chad, U.S. officials said on Thursday, a move that comes just days after Washington was forced to agree to remove its troops from neighboring Niger.

Earlier this month Chad’s air force chief ordered the U.S. to halt activities at an air base near the capital N’Djamena, according to a letter sent to the transitional government and seen by Reuters.

Pentagon spokesperson Major General Patrick Ryder said a portion of the U.S. troops in Chad would reposition out of the country.

He said it was a “temporary step” as part of an ongoing review of security cooperation with Chad, which would resume after the country’s May 6 presidential election.

A U.S. official, speaking on condition of anonymity, said a few dozen special forces troops who are in Chad as planners and advisers will move to Germany for now.

Interim President Mahamat Idriss Deby is running for election next month, making Chad the first of West and Central Africa’s junta-ruled countries to organise a vote. Opposition groups have flagged concerns about its credibility.

Until now, the vast central African country has been a key partner for Western and regional militaries in a joint fight against a violent Islamist insurgency in neighbouring West Africa.

In the letter dated April 4 to Chad’s minister of armed forces, Air Force Chief of Staff Idriss Amine Ahmed said he had told the U.S. defence attache to halt U.S. activities at Adji Kossei Air Base after “Americans” had failed to provide documents justifying their presence there.

Former colonial power France still has 1,000 troops and war planes based in Chad.

It has become all the more central to Western security strategy in the region since neighbouring Niger kicked out French troops after its junta seized power in a coup last year, following similar moves by military-led Mali and Burkina Faso.

In neighboring Niger, the junta asked the U.S. to withdraw military personnel from the country over disagreements with Washington on issues including progress on the country’s transition to democratic rule.

The United States has said discussions have begun on the withdrawal of forces from Niger, which until a coup last year had been a key partner for Washington’s fight against Islamist insurgents who have killed thousands of people and displaced millions more.