"The agreement is a positive step towards normalizing the relations between Chad and Sudan, which is a very important factor in resolving the tragic conflicts in both Darfur and eastern Chad," Mr. Ban's spokesperson, Michele Montas, said in a statement on the agreement signed on 3 May in Riyadh, Saudi Arabia.
"It is now crucial for the parties to honour their agreements and, in close collaboration with the United Nations and the African Union, to work together to achieve lasting peace and stability," Ms. Montas said.
She added that the Secretary-General commended King Abdullah Bin Abdul Aziz of Saudi Arabia, under whose auspices the agreement was signed.
More than 200,000 people have been killed and 2 million others displaced from their homes in the fighting in Darfur, and fears are increasing that the conflict is spilling over into neighbouring Chad and the Central African Republic.
An estimated 25,000 Chadians have sought refuge in West Darfur, despite the conflict in that part of Sudan, because of fighting across eastern Chad in recent months between rebels and Government forces, according to the UN High Commissioner for Refugees (UNHCR).