Foreign Office Minister Chris Mullin said the Sudan Liberation Movement/Army and the Justice and Equality Movement "should reconsider their current position and agree to the immediate resumption of the peace talks in Abuja without preconditions."

Previous rounds of peace talks in the Nigerian capital have failed to calm Sudan's troubled Darfur region, where fighting between government-backed Arab militias and African rebels has resulted in the deaths of more than 180,000 people, according to U.N. estimates.

"The current position of non-engagement is unacceptable and is unnecessarily delaying peace in Darfur," said Mullin, after meeting with Minni Minnawi of the Sudan Liberation Movement in London.

Fighting started in Darfur after rebels of ethnic African tribes took up arms, complaining of discrimination by the Arab-dominated government in Khartoum. A pro-government Arab militia, known as the Janjaweed, launched a violent counterinsurgency.