By Stephanie Hancock N'DJAMENA, Jan 20 (Reuters) - Violence in Sudan's Darfur region is stoking a "quiet war" between Sudan and Chad which will only end if both governments stop supporting each other's rebels, Washington's special envoy to Sudan said on Saturday. Andrew Natsios, speaking after meetings with two Darfur rebel groups in neighbouring Chad, said the different factions of the insurgency needed to adopt a unified position to bring an end to the four-year Darfur conflict which has killed 200,000 people. He called on Sudanese President Omar Hassan al-Bashir to implement the Darfur Peace Agreement signed in the Nigerian capital Abuja in May with some rebel groups. This deal could serve as the basis for a broader agreement with the remaining rebel factions, Natsios said. Asked about his talks this week with Chad's President Idriss Deby, Natsios said: "I've asked President Bashir to stop support for Chadian rebels that are destabilising Chad and I asked the Chadian government to stop supporting the rebellion in Darfur." "There is in fact a quiet war going on between the two countries, which is related in my view to the instability in Darfur," he told a news conference. "I think if we deal with the conflict in Darfur those tensions will diminish." Khartoum has repeatedly denied backing a long-running insurgency in remote eastern Chad against Deby's 17-year-old regime. Deby has likewise rejected Sudanese accusations that he supports the rebels in Darfur. Fighting erupted in Darfur in February 2003 when rebels took up arms against Bashir, accusing him of discriminating against the impoverished western region. The government responded by arming Arab militias to counter the rebellion. Some 2.5 million people have been forced from their homes in a conflict that Washington has termed "genocide". DEEP DIVISIONS U.S. Governor Bill Richardson of New Mexico negotiated a proposed 60-day ceasefire between Darfur rebels and the Sudanese government last week, but divisions among the insurgents have already undermined the deal and the rebels say the government has violated the truce with air strikes. Darfur commanders who rejected May's Abuja peace deal have formed a new alliance called the National Redemption Front (NRF) and renewed hostilities in June. Natsios met a leader of the NRF in the eastern Chadian town of Abeche on Friday, and also held talks with a representative of the Sudan Liberation Army (SLA). Sudan has rejected U.N. Security Council Resolution 1706 authorising some 22,500 U.N. peacekeepers and police to take over a struggling African Union mission in Darfur. In December, Bashir softened his position by agreeing to a "hybrid operation" in a letter to outgoing U.N. Secretary-General Kofi Annan. Natsios said that, while U.N. peacekeeping troops were a necessary component of resolving the Darfur crisis, the only long-term solution was a voluntary peace agreement between the Sudanese government and rebels. "The purpose of these troops is to stabilise the situation in the interim and protect innocent civilians, and then to help the peace agreement which is finally signed," he said.
