The European Union called on Friday for the "immediate cessation of hostilities" in the conflict-wracked Sudanese province of Darfur and urged Khartoum to provide protection from violence to all citizens.

The leaders, who discussed Darfur at a two-day summit in Brussels, expressed "deep concern about the appalling security, humanitarian and human rights situation in Darfur", as well as the recent outbreak of violence in southern Sudan.

The leaders called at the end of their summit for "immediate cessation of hostilities" and underlined "the obligation of all parties to respect human rights and international humanitarian law".

The US presidential envoy to Sudan was to meet senior NATO and EU officials in Brussels on Friday after failing to convince Khartoum to comply with agreements on the deployment of a joint United Nations-African Union peacekeeping force to Darfur.

The visit to Brussels by envoy Andrew Natsios comes after the United States confirmed this week that it was considering imposing a no-fly zone over Darfur if Sudan persists in its rejection of the peacekeepers.

The government of President Omar al-Beshir has rejected a UN resolution demanding the deployment of some 20,000 UN peacekeepers to replace the under-funded and ineffective AU force of 7,000 in Darfur.

In a compromise deal, Khartoum agreed in principle last month to a three-phase plan for deploying a hybrid force made up mostly of AU troops but beefed up by UN logistical support and commanders.

The EU leaders on Friday urged all the warring factions in Darfur to reach a peace deal, voicing concern that the ethnic conflict was spilling over Sudan's borders into neighbouring Chad and the Central African Republic

"The European Council (of EU leaders) urges all parties to enter immediately into dialogue with the objective of making the DPA (Darfur Peace Agreement) an all-inclusive peace agreement," they said in their its conclusions from the summit.

"The destabilising effects of the Darfur conflict in the wider region, in particular in Chad and the Central African republic are of great concern," they added.

In May, a faction of the rebel Sudan Liberation Movement (SLM) in Darfur signed a peace deal with the Khartoum regime to end the civil war. Two other rebel groups refused to sign, saying the accord did not meet all their demands.

The peace deal began running intro trouble last month, when the SLM faction said the Sudanese government had still done nothing to disarm the Arab militias known as the Janjaweed. These government-allied militias are accused of widespread atrocities against Darfur's black African population.

The Darfur conflict, which has been raging for nearly four years, has claimed between 200,000 and 300,000 lives and displaced more than 2.4 million people.