Washington - US President George W Bush said Wednesday he was frustrated by the slow pace of the United Nations in building a peacekeeping force to halt the violence in Sudan's Darfur region.

"The pace of action out of the United Nations is too slow," Bush said after meeting a leading human rights activist for Darfur, Halima Bashir.

The UN Security Council in July 2007 adopted a resolution to establish a peacekeeping mission in Darfur, but has been unable to find countries willing to contribute troops. Only about one-third of the 26,000 authorized size of the force has been deployed.

"I am frustrated with the pace of activities," Bush said. "The United Nations must expedite sending troops, peacekeepers, to provide security for the people."

The Bush administration has pledged logistical support for the mission.

The Sudanese government backed the so-called Janjaweed militias in their fight against rebel groups that began in February 2003. More than 300,000 people have been killed in the conflict regarded as the worst humanitarian crisis in the world.

The United States has placed sanctions on the Sudanese leadership for failing to halt support for the militia. Sudanese President Omar al-Bashir initially refused to allow the deployment of the UN force but relented under intense international pressure. He has refused to allow American troops or soldiers from some European countries into Sudan.

Al-Bashir was indicted for war crimes by the International Criminal Court in July. (dpa)