A team of British troops will be sent to join the Nato effort in Kosovo, Sir Michael Fallon has announced.
The Defence Secretary said almost 30 troops will travel early next year to join the Nato Kosovo Force (KFOR) on a 12-month deployment.
Sir Michael said "significant security and stability challenges" remained in the western Balkans.
The UK's contribution to the mission will focus on supporting KFOR's ability to carry out intelligence, surveillance and reconnaissance operations. The personnel will be based at KFOR's headquarters in Kosovo's capital Pristina.
Sir Michael said: "There are significant security and stability challenges in western Balkans.
"Nato remains a cornerstone of our defence. By continuing to defend the security of Europe, Britain's security is strengthened at home."
KFOR began as a peacekeeping force in the late 1990s following the war which saw Kosovo break away from Slobodan Milosevic's Yugoslavia.
It now has about 4,300 troops from some 30 countries helping ensure security in Kosovo.