Secretary of State Colin Powell met Thursday with Sudanese southern rebel leader John Garang on efforts to conclude Sudan's north-south peace process. Mr. Garang endorsed Mr. Powell's depiction of violence in Sudan's western Darfur region as genocide.

The secretary's meeting with Mr. Garang marked a return to personal diplomacy on the north-south Sudanese peace process after months of preoccupation with the Darfur crisis.

The north-south conflict raged for nearly two decades before Mr. Garang's Sudan People's Liberation Movement reached a truce and began Kenyan-mediated peace talks with the Khartoum government in 2002.

The two sides signed several protocols in May that ostensibly resolved remaining issues, but implementation has stalled amid haggling over details.

Speaking with reporters after seeing Mr. Powell, Mr. Garang said he supported the U.S. finding that the Sudanese government's use of Arab "Janjaweed" militiamen against Darfur rebels and black African villagers supporting them is an act of genocide.

"That's what it is isn't it? When you have a government that uses tribes against other tribes as a counter-insurgency strategy, then embedded in that concept of using people against people, that's the definition of genocide or ethnic cleansing, so indeed it is genocide, yes," he said.

Mr. Garang said he thinks the U.S. genocide finding will affect Sudan's overall peace process in a positive way, by energizing international efforts to secure the civilian population in Darfur and obliging the parties to work harder on the parallel north-south peace track.

He said the SPLM, for its part, is ready to return to the negotiations in Naivasha, Kenya and deal with the remaining issues, which he said are "technical in nature."

"We have only to negotiate a comprehensive cease-fire agreement and to negotiate the implementation modalities," he said. "What we can do as a movement is to go back to Naivasha and complete these two issues that are left, so that we have a comprehensive peace agreement in place, and we implement that agreement, and that will help in resolving the situation in Darfur."

Mr. Powell told senators the Khartoum government appears unwilling to resume senior level talks with the SPLM, claiming that it must focus on Darfur.

He said a comprehensive north-south agreement would "bolster" efforts to resolve the crisis in Darfur by providing a legal basis for a political solution, and opening up the political process in Khartoum.

The secretary of state said he has told Sudanese President Omar el-Bashir and other leaders in Khartoum that the United States wants a united, prosperous and democratic Sudan, and is fully prepared to work with them toward that end.