British Prime Minister Tony Blair has warned Sudan it is nearing the "crunch point" for Khartoum to enforce the peace in Darfur or risk isolation and unspecified action by the international community.
Mr Blair met Sudanese Vice President Salva Kiir in London and told him "everyone must stop fighting and resume dialogue with the people who did not sign up to the peace agreement," Blair's spokesman told reporters.
"We are reaching the crunch point. It's important that the Sudanese government be in no doubt at all of our seriousness," he said at a briefing about the two leaders' talks.
A boy clings to his mother in a Darfur refugee camp
Mr Blair told Mr Kiir there must be "clear progress" by November 24th when African Union leaders meet to discuss Darfur.
More than 200,000 people have been killed and 2.5 million driven from their homes to live in camps in Sudan and across the border in Chad since the start of fighting in Darfur in 2003.
The conflict has pitted mostly non-Arab rebels against the Arab-dominated government and Janjaweed militia. All sides have been accused of grave human rights violations.
A shaky peace agreement was signed in May by only one of the Darfur rebel factions and the government.
Since then, tension has been rising between Khartoum and the West over a US-British backed UN Security Council resolution that calls for the dispatch of 22,500 UN troops and police to Darfur.
Khartoum has rejected the deployment of a UN force, saying it is an attempt at recolonisation by Western powers and says AU forces alone should have the job of patrolling Darfur. But the 7,000 AU forces in Darfur have been unable to halt the violence.
"The Sudanese government know they face isolation if they do not respond to the will of the international community," Mr Blair's spokesman told reporters, but would not be drawn on what that would mean in practice.
"It would be better to let the Sudanese government absorb the message before we talk in public about that," he said, adding "private messages" were better than public threats at this stage.