Niger says it will not be intimidated into leaving Mali a day after nine of its peacekeepers were killed in an ambush in the neighboring country.

Gunmen on motorbikes on Friday attacked a convoy of Niger's troops who are participating in a U.N. peacekeeping mission in Mali. The ambush was the deadliest attack on the U.N. force yet.

U.N. troops are trying to stabilize Mali's north, which fell under the control of Tuareg separatists and then al-Qaida-linked Islamic extremists following a 2012 coup. A French-led intervention last year scattered the jihadists, but attacks on the U.N. force have been increasing lately.

Niger's president, Mahamadou Issoufou, vowed Saturday that the West African country would stay in Mali and continue to fight terrorism.