The U.S. special envoy for Sudan, Andrew Natsios, has begun a 10-day visit to the east African country, where he hopes to help peace efforts both in southern Sudan and the war-torn Darfur region.

Natsios arrived in the capital, Khartoum, late Wednesday.  He is scheduled to meet with Sudanese officials Thursday to discuss the situation in Darfur and is scheduled to travel to the region later this week.

The U.S. envoy's Darfur visit comes ahead of peace talks between Darfur rebels and the Sudanese government, scheduled to begin in Libya October 27.

U.S. diplomats say Natsios also is expected to travel to southern Sudan where a 2005 peace agreement is said to be in jeopardy.  That agreement ended 20 years of civil war between northern and southern Sudan.

The diplomats say Natsios will help negotiate border demarcation in the oil-producing central Abiye region.

More than two million people died during Sudan's civil war.  Nearly three years of peace talks led to the final North-South Comprehensive Peace Agreement (CPA), signed in January 2005.  That agreement granted southern Sudan autonomy for six years, after which a referendum for independence is scheduled to be held.

Darfur has experienced more than four years of war between rebel groups, the Khartoum government and militias believed to be receiving government support.  The fighting has killed an estimated 200,000 people, and displaced more than two million others.  The violence also has spilled over into neighboring Chad and the Central African Republic.

Some information for this report was provided by AFP.