The UK Ministry of Defence (MoD) is to deploy additional forces to support the Nigerian armed forces against Boko Haram, an Islamic extremist group based in north-eastern Nigeria.
The MoD will double the number of personnel deployed on training tasks in Nigeria during 2016.
It will also deploy a specialist team to provide assistance in countering improvised explosive devices, as well as medical training and advice.
A new Royal Air Force (RAF) training team will train the Nigerian Air Force in airfield defence and counter insurgency.
UK Defence Secretary Michael Fallon said: "Boko Haram is a brutal organisation that has murdered and kidnapped innocent civilians. We stand united with Nigeria in its efforts to defeat them.
"Stepping up our training efforts will help support the Armed Forces of Nigeria (AFN) for crucial counter-insurgency operations."
The decision follows the Nigerian military's appeal to the international community for assistance, following a recent attack on the north-eastern town of Baga.
The extremist group attacked Baga and the surrounding villages after overrunning the headquarters of the Multinational Joint Task Force, which consists of soldiers from Nigeria, Niger and Chad. The group reportedly killed 2,000 people.
Claimed to be the deadliest massacre in the group's five-year insurgency, hundreds of civilians were wounded, and at least 20,000 were forced to flee.
Around 130 UK military personnel are currently in Nigeria on a wide range of training tasks.
Tasks include training in infantry skills, civil-military affairs, media operations, command and leadership, IED-awareness, and support to Nigerian military training schools and establishments.