Annan urged the UN Security Council to take immediate steps to stop the violence in Darfur, which has killed at least 70,000 people and displaced 2 million.
"Darfur's people are living in hell," said Chadian President Idriss Deby at the start of the Darfur talks in Chad's capital N'Djamena, which were also attended by international mediators and African Union (AU) Commission Chairman Alpha Oumar Konare.
"We hope the parties will declare a total and definitive ceasefire. It is time for them to respect their commitments," Deby told the talks' opening session late on Wednesday.
Sudanese government officials and Darfur's two main rebel groups - the Sudan Liberation Movement and the Justice and Equality Movement - attended the N'Djamena talks, which are meant to prepare for full political negotiations.
The talks are due to end on Thursday.
"We hope the parties will declare a total and definitive ceasefire. It is time for them to respect their commitments"
Nigeria's President Olusegun Obasanjo, current chairman of the 35-member AU, said on Wednesday he hoped full peace talks would start again in Abuja at the end of February.
Konare said a team of AU and Chadian officials would be sent to Darfur after the talks to map out the positions of the belligerents and check on the commitments made.
The leaders of Sudan and Chad on Wednesday warned the international community not to send non-African troops to Darfur or to impose sanctions.
The AU has 1400 troops in Darfur and expects the force to grow to more than 3000.