"We are very concerned by the situation in Chad," said Jean-Marie Guehenno, the French head of UN peacekeeping operations.
"The figures speak for themselves. There are in Chad more than 200,000 refugees, more than 50,000 IDPs (internally displaced persons)," he noted. "So we are looking at ways in which a peace operation could prevent the tragedy of Darfur from expanding further in a bigger tragedy in Chad and the CAR."
He spoke after briefing the UN Security Council on developments in Sudan following Khartoum's decision to expel UN special envoy Jan Pronk over his criticism of the Sudanese army's performance in Darfur.
Guehenno said several options were under consideration to assist refugees and internally displaced in Chad and CAR, although he did not give details.
He added that a UN assessment team would be sent to the two countries for that purpose.
"People are going to look at what practically can be done. We would want to be as expeditious as possible because we feel that this is a situation that needs to be urgently addressed," Guehenno said.
In recent weeks, UN diplomats have spoken of the possibility of deploying a police force to Chad to protect refugee camps.
The UN refugee agency said earlier this month that it was deeply concerned about clashes in Darfur within kilometres (miles) of a camp for thousands of people who have fled to neighbouring Chad.
Jennifer Pagonis, a spokeswoman for the UN High Commisioner for Refugees (UNHCR), said heavy fighting between the Sudanese military and Darfur's rebels had raised fears for the safety of the 26,300 people in Oure Cassoni camp, which is only five kilometres (three miles) inside Chad.
The UNHCR is caring for more than 200,000 Sudanese refugees who have fled to Chad to escape over three years of fighting in Darfur.
In CAR, the UNHCR said two weeks ago that the repatriation of about 10,000 Sudanese refugees from the country could resume at the end of October after a six-month delay.
Relations between different communities in the region have been strained since 2003 when a civil war started in Darfur between local rebels and pro-government militia. At least 200,000 people have died there from the combined effects of fighting, famine and disease, according to the UN.

Copyright AFP (Agence France-Presse), 2006