* Kerry says time is tight to avert humanitarian disaster
* Sudan striking more conciliatory tone towards U.S.
* Khartoum says expelled aid groups remain unwelcome
(Adds details and background)
By Alastair Sharp
KHARTOUM, April 16 (Reuters) - U.S. Senator John Kerry said after talks with senior Sudanese officials on Thursday Khartoum would allow some foreign aid to be restored in its western Darfur region but that it was not sufficient.
"Time is of the essence to avert a humanitarian catastrophe," said Kerry, who heads the U.S. Senate’s Foreign Relations Committee and is leading a congressional delegation to Sudan.
Kerry arrived on Wednesday just two days after Sudan’s President Omar Hassan al-Bashir struck a more conciliatory tone towards Washington, seen by Khartoum in the past as an enemy.
International experts estimate some 200,000 people have been killed and 2.5 million have been driven from their homes during almost six years of ethnic and politically driven fighting in Sudan’s west. Khartoum puts the death toll at around 10,000.
Last month, the International Criminal Court issued an arrest warrant for Bashir on charges of masterminding war crimes in Darfur. Sudan expelled 13 foreign aid groups it accused of helping build the charges against Bashir.
Kerry said a new dialogue had been brought about by U.S. President Barack Obama’s special envoy to Sudan, Scott Gration, and the willingness of the Sudanese government.
"(As a result), some of that capacity for humanitarian assistance will be restored. Today I emphasised to all the leaders I met with that a partial restoration of capacity is not sufficient," said Kerry.
Sudan’s U.N. Ambassador Abdalmahmoud Abdalhaleem told Reuters in a telephone interview: "The expelled organisations for us are a closed file. It’s irreversible (that they will not be allowed back into Darfur).
"We’ve discussed with Scott Gration and John Kerry that the government can accept new humanitarian aid (organisations) — those who are committed to humanitarian ideals."
Some 4.7 million people rely on humanitarian aid in Darfur, where the United Nations runs its largest aid operation in the world with the help of non-governmental organisations.
Sudan has said Sudanese groups have been filling the gaps left by the expelled groups and that there is no problem with aid distribution. Foreign aid groups dispute this.
Kerry is due to travel to Darfur on Friday to see the situation first-hand and meet local leaders and U.N. officials.
He called on the government and Darfur rebel groups to resume negotiations to seek a peace deal.
(Writing by Ralph Gowling; Editing by Ralph Boulton)