Close to 200 Nigerian troops are due to arrive in Mali to help fight Islamist insurgents in the country's north.
It is the first West African contingent to join France's anti-rebel operation launched in Mali on Friday.
In total, 3,300 regional troops will be deployed in the conflict under a UN Security Council Resolution. Chad has confirmed it will send 2,000 troops.
Meanwhile French and Malian forces have started the first major ground operation against the militants.
Sources say street battles broke out between soldiers and rebels in the town of Diabaly, 350km (220 miles) north of the capital Bamako on Wednesday.
Islamists entered Diabaly on Monday, taking the town from Malian forces. French fighter jets have since attacked the rebel position.
A company of 190 Nigerian soldiers will be flown from the northern city of Kaduna into Mali on Thursday, the BBC's Will Ross in Kaduna reports.
Nigeria will lead the West African regional force. It has promised to send a total of 900 troops as well as fighter jets.
Chad has also confirmed 2,000 soldiers will join the anti-rebel operation in Mali.
"We intend to send an infantry regiment and two support battalions," Chadian Foreign Minister Moussa Faki Mahamat told Radio France Internationale.
Benin, Ghana, Niger, Senegal, Burkina Faso and Togo have also pledged to take part.