Chad has warned the European Union that delay in deploying peacekeepers on its eastern border with Sudan risked "setting the region ablaze", and it accused its neighbour of arming Chadian rebels to block the EU mission.

Europe hopes to send around 4,000 "Eufor" troops in the coming weeks to protect aid operations in eastern Chad and adjoining northeastern Central African Republic, complementing a much larger UN-African Union force planned for Sudan's Darfur.

Chad's government held a crisis meeting late on Wednesday to confront what it said was the threat of attack from its larger Chinese-backed neighbour Sudan, which has resisted efforts to deploy international peacekeepers to war-torn Darfur.

"(This) new aggression on the greatest scale aims to destabilise Chad and block the deployment of Eufor forces in Chad and Central African Republic as well as the formation of a hybrid UN-African force in Darfur," government spokesman

Hourmadji Moussa Doumgor told state radio after the meeting. "Any delay in deploying the hybrid forces in Darfur and those of Eufor in Chad and Central African Republic will inevitably result in the region being set ablaze," he said, warning Sudan-backed rebel attacks against Chad were imminent.

Government officials in Khartoum, which accuses Chad in turn of aiding Sudanese rebels, could not be reached for comment.

The conflict in Darfur since 2003 has spilled refugees and violence over the border into eastern Chad, where aid workers are struggling with widespread insecurity as they help more than 400,000 Sudanese and local refugees living in sprawling camps.

The EU force was originally due to deploy in November but has been repeatedly delayed while stretched European armies struggle to assemble equipment needed. A diplomat in Brussels last week called the latest target date of January "ambitious".

Around half the EU force will come from France, which has military units stationed in Chad and Central African Republic under defence accords with these former colonies.