Washington - US President George W said Monday he has authorized the US military to conduct airlift missions into Sudan's Darfur region to transport vehicles and equipment for the UN peacekeeping mission.

Bush approved US support for the mission before meeting with Sudanese Vice President Salva Kiir, a rival of President Omar al-Bashir. Al-Bashir has been the target of US sanctions for his failure to reign in the government-backed militias waging war in Darfur.

Bush's nod allows the State Department to immediately begin sending supplies into Darfur for the UN mission. Bush credited Kiir for working to bring the rebel groups together to negotiate peace with Khartoum.

"He is taking the lead in helping the rebels come together so that there would be a more unified voice in hopefully negotiating a peace with the Bashir government," Bush said.

The United Nations is leading the mission in partnership with the African Union, which has been ineffective at bringing an end to the violence that erupted in February 2003 between government-backed Janjaweed militias and rebel groups.

More than 300,000 people have been killed in the conflict regarded by the Bush administration as genocidal. More than 1 million people have been forced to flee.

Earlier, Bush's national security adviser, Stephen Hadley, rejected accusations the United States has been to slow to respond to the crisis in Darfur, saying Washington took the lead in bringing international attention to the violence and sought UN Security Council sanctions.

"The United States will continue to lead the international community to stand by the people of Darfur and to deploy and support the UN peacekeeping operation," Hadley said in a statement.

Kiir, a former rebel leader in a separate North-South conflict that ended in a 2005 peace agreement, is also president of semiautonomous southern Sudan. Implementing that agreement was also a topic during the White House meeting with Bush.

Bush last month expressed the frustration over the slow pace of assembling the UN peacekeeping mission approved by the Security Council in July 2007.

"The pace of action out of the United Nations is too slow," Bush said December 10.

The United Nations 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.

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