The ministry did not specify when the "US military trainers" arrived or were due to arrive.

"The Defence Headquarters (DHQ) wishes to announce the arrival of about 100 United States military personnel and associated equipment at Bauchi Airfield," the statement said.

"The arrival is planned and deliberate following a formal request by the Federal Government of Nigeria to the US government to support a clearly defined military training requirement, technical support and intelligence sharing with the members of the Armed Forces of Nigeria."

Nigeria is facing a longstanding jihadist insurgency in the northeast, a conflict between farmers and herders in north-central regions, separatist violence in the southeast, and kidnappings for ransom in the northwest.

US President Donald Trump has claimed that Christians in Nigeria are being "persecuted" and are victims of "genocide" perpetrated by "terrorists".

But Abuja and most independent experts say the violence in Nigeria indiscriminately affects both Christians and Muslims.

On December 25, the US military conducted airstrikes in Nigeria's Sokoto State. Nigerian authorities subsequently said the action was coordinated with them and it targeted Islamic State jihadists.

For the announced deployment, Nigeria's DHQ said: "The US personnel are technical specialists serving strictly in an advisory and training capacity. They are not combat forces."