WASHINGTON - The United States pressed Sudan on Tuesday to cooperate more in enabling the deployment of a joint United Nations-African Union force into its violent Darfur region.

Sudan's State Minister for Foreign Affairs Al-Samani Al-Wasiyla led a delegation in talks with U.S. special envoy to Sudan Andrew Natsios in Washington on Tuesday and met senior State Department officials on Monday.

"We obviously continue to stress our long-standing view that we need to see full Sudanese cooperation with the deployment of the AU/UN hybrid force and emphasized the importance of that force as part of achieving an overall settlement of the crisis there," said State Department spokesman Tom Casey.

Al-Wasiyla requested the meetings in Washington and a U.S. official said Khartoum felt it had not been given enough credit for agreeing to the so-called hybrid force.

Last month the U.N. Security Council passed a resolution to send 26,000 U.N. and African Union peacekeepers to the remote western Sudanese region in a bid to end more than four years of killing, raping and looting there.

The joint mission, which Khartoum opposed for months but now says it will accept under certain conditions, is set to be in place early next year.

Sudan's embassy did not immediately return calls to comment on the meetings in Washington.

In May, the United States tightened sanctions against Sudan and has made clear there must, among other signs, be tangible progress on Darfur, an end to the bombings of villages and a cessation of harassment of aid workers and diplomats before these will be lifted.

But recent Sudanese government actions have disappointed Washington, including the expulsion over the past week of European and Canadian envoys as well as the local head of the U.S.-based aid group, CARE.