WASHINGTON, Jan 8: US Secretary of State Colin Powell will exit international diplomacy after attending the signing ceremony of a peace agreement in Kenya on Sunday between the Sudanese government and rebel forces, the State Department said.

Mr Powell, who will be replaced by National Security Adviser Condoleezza Rice later this month, played a key role in arranging the peace deal that he hopes would end Africa's longest-running civil war.

When he returns home later this week, Mr. Powell will still have few days before the Jan. 20 inauguration of the second Bush government for working with his successor and for saying farewell to the State Department that he ran for four years.

After completing a tour of tsunami-ravaged countries in Asia on Friday, Mr. Powell will travel to the Kenyan capital, Nairobi, which will probably be the final stop on his overseas mission. During his two-day stay in Kenya, he will meet Kenyan officials and also confer with Sudanese leaders on the crisis in Sudan's western Darfur region.

Sudanese rebel and government leaders are expected to sign a peace accord in Nairobi on Sunday, aimed at ending Sudan's long-running north-south civil war.

In Washington, State Department's deputy spokesman Adam Ereli briefed reporters on Mr. Powell's last international engagement, calling the expected accord "a watershed in the decades-old conflict in Sudan." Mr. Powell's visit, he said, was "a recognition of the importance of this agreement."

Last year, the outgoing secretary of state also visited Darfur where a separate conflict between a government-backed militia and Sudan's ethnic Africans has caused thousands of deaths and displaced hundreds of thousands.

Mr. Ereli said Mr. Powell's visit will be an opportunity to convey to the Khartoum government and southern rebels the value the United States places on resolving the country's remaining political disputes through dialogue and negotiation.

He said the degree to which the Sudanese government tries to settle the Darfur conflict, and end "rampant human rights abuses" there, will have a large bearing on the future shape of US-Sudanese relations.

The north-south conflict erupted in 1983, pitting the Muslim government in Khartoum against mainly Christian and animist rebels seeking autonomy for the south. It led to the deaths of more than 2 million people, mainly from war-related hunger and disease.

The African Union, an organization of 53 African nations, played a key role in peace negotiations and the United States actively supported the process, despite frustrating delays and last minute glitches.

The agreement now being signed in Nairobi provides for the sharing of legislative power and natural resources, including Sudan's growing oil revenue.

John Garang, head of the southern rebels, will join a new government of national unity as first vice president and the Sudanese government will withdraw at least 91,000 troops from the rebel-controlled south.

The forces must pull out within 21/2 years, while a proposed government for the autonomous southern Sudan will raise a separate army using its share of oil and tax revenues as well as international aid.

The rebels will have eight months to withdraw their forces from northern Sudan. They must pull out 30 percent of their fighters within four months of the signing of the accord.

The rebel Sudan People's Liberation Army and government forces also agreed to either disband their allied paramilitary groups in southern Sudan or merge them with rebel and government forces within a year.

Government and rebel forces each will contribute 20,000 troops to new, integrated army units. Rebels and the government also agreed to demobilize an unspecified number of troops.

Under the accord, Sudan will rewrite the constitution to ensure that Shariat is not applied to non-Muslims in the country.