U.S. Deputy Secretary of State Robert Zoellick held talks with Sudanese First Vice President Salva Kiir Mayardit Tuesday and announced he will make another trip to Sudan next week. Mr. Salva Kiir succeeded the late John Garang in August as the main southern Sudanese leader in the country's new unity government.

Mr. Zoellick has been the Bush administration's point-man for Sudan diplomacy, and the mission he begins early next week will his fourth to the region since assuming office in January.

The deputy secretary announced his travel plans following a two-hour meeting here with Mr. Salva Kiir, who is paying his first visit to Washington since taking over the political roles of John Garang, who was killed in a helicopter crash at end the of July.

Mr. Salva Kiir became both the First Vice President of the Sudanese unity government and the head of the former southern rebel army, the Sudan People's Liberation Movement, the SPLM.

His talks in Washington also included brief meetings Tuesday with Secretary of State Condoleezza Rice and Vice President Dick Cheney, and he is to meet Congressional leaders Wednesday.

At a joint press appearance with Deputy Secretary Zoellick, Mr. Salva Kiir said no one had expected the SPLM to remain united after the death of the charismatic Mr. Garang, who headed the movement for decades.

But he said it has been stabilized and has begun moving, albeit slowly, toward implementing the north-south accord and setting up a southern regional government that could become independent after a referendum on the region's future to be held in six years.

Mr. Salva Kiir also said he expects progress toward ending violence in the western Darfur region now that the partners in the unity government in Khartoum, the SPLM and the Islamic-led National Congress Party, are forming a joint delegation for the Darfur peace talks in the Nigerian capital Abuja.

"Now that we have agreed in principle that we will put up a joint delegation representing the Government of National Unity for the next round of talks in Abuja, I think we will be in a position to contribute effectively to a solution in Darfur," he said. "Of course, saying so will not be enough unless we put it into practice."

Mr. Zoellick said he also telephoned Sudanese Vice President Ali Osman Taha Tuesday about his pending Sudan mission, which will include stops in Khartoum, the southern regional capital of Juba, and in Darfur.

The deputy secretary said he will press the parties to move ahead on institution-building in line with the north-south peace accord, while also urging the two main Darfur rebel groups to end political bickering that has stalled the Abuja talks.

"One reason that I'm going to Sudan is to try to make sure that the policies that are represented under the Comprehensive Peace Accord are on track and all the parties are undertaking them," he said. "I also hope to meet some of the rebel groups from Darfur to insure that they come together in a unified position, because in the problems of Darfur, it's not just a question of providing security or humanitarian support, but eventually moving toward some peace accord."

Mr. Zoellick, under questioning, ruled out an early end to U.S. sanctions against Sudan, which were imposed a decade ago because of human rights abuses and the Khartoum government's links to terrorism.

Mr. Salva Kiir maintains the sanctions should end because Sudan's two-decade-long north-south civil war is over.

However the deputy secretary said the Bush administration first needs to see ongoing results on both Darfur and implementation of the comprehensive peace accord.