WASHINGTON – Deputy Secretary of State Robert Zoellick was dispatched to Africa yesterday to push for a peace agreement to end political and ethnic conflict in the Darfur region of Sudan.

Mr. Zoellick’s trip was announced after the first day of a two-day extended deadline for a settlement ended without a pact. Sudan’s government has said it will accept the accord, but rebel groups are still pressing additional demands.

“As long as the parties are talking, there’s always a chance for an agreement,” Secretary of State Rice said. But she declined to predict the outcome.

At a news conference, Ms. Rice said President Bush felt “very strongly and very passionately” about both the need for an agreement and getting a robust and largely African security force in to protect the people of Darfur.

“It takes time,” she said, “We need to shake the trees a little bit, shake the bureaucracy a little bit and say to people: ‘It’s not acceptable to wait any longer for at least the planning for a robust security force.'”

Disarming militias and integrating them into an armed force are among matters that must be resolved before completion of a deal. Sunday’s deadline was extended at American request.