Chad has begun withdrawing its troops from Mali, where for months they have helped battle Islamist militants in the country's north.
Chad's President Idriss Deby said his troops have "accomplished their mission" and are not able to fight the type of guerrilla war now emerging in Mali.
After France, Chad's 2,000 troops were the most sent by any nation to help Malian forces reclaim the northern part of the country. France pulled out 100 soldiers last week in the first step of its phased withdrawal.
Three Chadian soldiers died in a suicide bombing last week in northern Mali, while 13 others were killed in battling militants in February.
A U.N. force of up to 11,000 troops is expected to take over security while efforts are made to stabilize Mali and hold new elections.
Mali plunged into crisis last year when soldiers overthrew the government, allowing al-Qaida-linked militants to take over the north.