American-led talks to halt Sudan’s war, convened at an exclusive Swiss ski resort, ended after 10 days on Friday with agreements to deliver food and medicine to millions of starving Sudanese in the country’s most famine-stricken areas.

But the mediators failed to broker a cease-fire, or even to get both sides around the table, after Sudan’s military refused to show up. Frustrated American and Arab diplomats said the breakdown exposed the disarray and internal divisions in Sudan’s weakened military, which are a major obstacle to ending Africa’s biggest war.

The United States hoped the talks in Villars-sur-Ollon, a picturesque village 80 miles by road from Geneva, could break an eight-month diplomatic deadlock. The military and its foe, the Rapid Support Forces, or R.S.F., have not held direct talks since January. Since then, war has spread, bringing a widespread humanitarian crisis that this month led to a rare declaration of famine.

In a sealed-off area inside a hotel that was otherwise occupied by unsuspecting tourists, diplomats from Saudi Arabia, Egypt, the United Arab Emirates and Switzerland attended the talks. So did representatives from the African Union and the United Nations.

The R.S.F. sent a delegation that the Swiss housed in lakeside town 25 miles away.

At one point this week, Tom Perriello, the United States envoy to Sudan, broke away from the talks and flew to Cairo to meet an official Sudanese delegation, hoping to coax its members to attend. But the Sudanese sent delegates who the Americans and Egyptians thought were not interested in peace. Egypt’s intelligence chief, Abbas Kamel, who had brokered the meeting, called it off at the last minute, according to two officials who spoke on condition of anonymity because of the sensitivity of the negotiations.