Sudan has told the United States it will allow some aid back into its Darfur region, US Senator John Kerry told reporters on Thursday. “Thanks to the leadership of the president's special envoy General Scott Gration and thanks to the willingness of the government here to engage in a new dialogue with us, some of that capacity for humanitarian assistance will be restored,” Kerry told reporters after meeting senior members of the Sudanese government. But Kerry, who heads the US Senate's Foreign Relations Committee, said more would need to be done. “Today I emphasized, to all the leaders I met with, that a partial restoration of capacity is not sufficient,” Kerry said. “Time is of the essence to avert a humanitarian catastrophe,” he said. Thirteen international aid groups were expelled from Sudan after the International Criminal Court issued an arrest warrant for Sudanese President Omar Hassan Al-Beshir in March. It was not immediately clear if any of the expelled aid groups would be allowed to return. Kerry will travel to Darfur on Friday to visit a camp and meet with local leaders and UNAMID officials. Gration will return to Sudan in early May to assess progress and continue discussions.