Nato urged to intervene in Darfur as donors pledge £110m for peace effort

International donors have pledged an additional £110m to help to expand an African force attempting to halt the continuing violence in Darfur, but the funds fell well short of target and seven former foreign ministers said it was time for Nato to send troops.

Britain pledged £6.6m at a conference in Addis Ababa where the US contribution of £27m was dwarfed by Canada's £74m to help to increase the number of troops in Darfur from 2,500 to 12,300 over the coming year. The African Union, which desperately needs logistical support for its mission, is looking for an additional £398m.

But the former foreign ministers, including Madeleine Albright and Robin Cook, stressed that after two years of failing to resolve the conflict in the western Sudan region, the international community now needed to put Nato troops on the ground under UN authorisation.

In an open letter published in the International Herald Tribune, they urged the UN Security Council to establish a no-fly zone over Darfur to be enforced by Nato aircraft.

The conflict has left more than 180,000 people dead and forced more than a million from their homes after Arab militias backed by the Sudanese government mobilised to quash a rebellion by the largely black African community in Darfur.

The UN secretary general, Kofi Annan, said there was now a race against time to help the civilian population because of the approach of the rainy season. "If violence and fear prevent the people of Darfur from planting and growing crops next year, then millions will have to be sustained by an epic relief effort," he said.

Western countries have been reluctant to commit troops to Sudan - which in any case is opposed to a foreign peacekeeping force - because of the negative perception of a Western intervention in another Muslim country after the Iraq invasion. The Nato secretary general, Jaap De Hoop Scheffer, said that while Nato was ready to supply airlift capability and training for AU peacekeepers, "the African Union has to remain in the driving seat".