Paris: The international community has failed in its responsibility to halt the killings in Darfur and must find a way to force Sudan to accept an international force to end the violence, the United States said on Sunday.

Speaking on the eve of an international meeting on the humanitarian crisis in the western Sudanese region, US Secretary of State Condoleezza Rice criticized major powers for not having ended violence that is now in its fifth year.

"I will be very frank. I do not think that the international community has really lived up to its responsibilities here," Rice told reporters at a news conference with French Foreign Minister Bernard Kouchner.

"Ultimately this is going to come down to will," Rice added. "Are we prepared to make the difficult choices in the international system that will, I believe, persuade and compel Khartoum to do what it must?"

Sudan on June 12 agreed to a combined United Nations and African Union peacekeeping force of more than 20,000 troops and police, but many diplomats doubt Khartoum will keep its word.

The aim of the force is to stop the violence in Darfur, where international experts estimate 200,000 people have died and 2.5 million have been expelled from their homes in more than four years of strife. Sudan says 9,000 people have died.

The Darfur problem dates back to early 2003 when non-Arab rebels took up arms, accusing the government of not heeding their plight in the remote, arid region. Khartoum mobilized Arab militia, known locally as Janjaweed, to quell the revolt.

The Janjaweed embarked on a campaign of killing, pillaging and rape. In the past year rebel groups have fought each other and also attacked civilians.