U.S. Ambassador Samantha Power urged the UN Security Council on Friday not to reduce or close the joint UN-African Union peacekeeping mission in Darfur, saying conditions in Sudan's conflict-wracked western region are getting worse.

She called for UN sanctions and an arms embargo on Darfur to be enforced and said it's time to move beyond "the failed peace processes and broken agreements" toward a political solution, starting with a real cessation of hostilities.

Darfur has been in turmoil since 2003, when ethnic Africans rebelled, accusing the Arab-dominated Sudanese government of discrimination. Rights groups charge the regime retaliated by unleashing Arab militias on civilians, a claim the government denies.

Sudan ordered the more than 20,000-strong peacekeeping force out of Darfur late last year.

But Assistant Secretary-General for Peacekeeping Edmond Mulet made clear last week it will not be leaving quickly.

He said the "exit strategy," being discussed by the UN, AU and Sudan requires council-endorsed benchmarks to be met and requires a political solution based on direct talks between the parties starting with a halt to violence.

Power issued her statement after an informal closed meeting of the council to discuss the situation in Darfur.

Two of the panelists, Sudanese lawyer Abdelrahman Gasim and Sudanese activist Hawa Abdallah Mohammed Salih, who was born in North Darfur, said afterward they told the council it should do more to make sure the U.N. force fulfills its mandate to protect civilians.

Power said their stories make clear that Darfur "continues to burn after more than 10 long, bloody years."

"The takeaways from today's meeting are clear: now is not the time to give up on Darfur; now is not the time to withdraw U.N. peacekeepers; and now is not the time to abandon the people of Darfur," she said.