KHARTOUM, July 3 (Reuters) - Sudan pledged on Saturday to disarm Arab militias, known as Janjaweed, who have driven more than one million Africans from their homes in west Sudan's Darfur region and to accept human rights monitors in the area.

"The government of Sudan commits itself to ... Immediately start to disarm the Janjaweed and other armed outlaw groups," it said in a communique issued jointly with the United Nations and signed at Khartoum airport before the departure of U.N. Secretary-General Kofi Annan.

Annan has been visiting Sudan and neighbouring Chad, including refugee camps in both countries, to assess the situation and put pressure on the Sudanese government to give aid agencies and monitors greater access to displaced villagers.

The United Nations says two million people have been caught up in fighting in Darfur between Arab nomads and African villagers, and that the resulting flood of African refugees has created the world's worst humanitarian crisis.

A long conflict between nomadic Arab tribes and African farming communities over scarce resources in Darfur intensified when a rebellion broke out last year, and rebels accuse Khartoum of arming the Janjaweed militia. The government denies this.

About 200,000 people have fled to Chad and aid agencies have said thousands could die of disease and hunger during the coming rainy season unless a massive aid operation is set up.

The United States raised the possibility on Friday of sanctions against Sudan if the government did not stop the militia attacks in Darfur.

The Bush administration has circulated a draft resolution that would impose an arms embargo and travel ban on the Janjaweed, and U.S. officials briefed the U.N. Security Council on Friday on the Darfur humanitarian crisis.

In the Khartoum communique, the Sudanese government promised to deploy human rights monitors to document abuses by all sides in Darfur.

It also pledged to ensure no militias were present near the camps set up for the one million displaced people and to deploy a "credible and respected police force" to protect them.

RIGHTS GROUP SCEPTICAL

A spokeswoman for the rights group Human Rights Watch was sceptical about the government's pledges, telling BBC radio "The Sudanese government has made other promises and rarely honours what it promises to do ... it takes a lot more pressure..."

"I doubt they will honour what they've agreed to."

African Union (AU) monitors in Darfur are authorised only to investigate violations of a shaky ceasefire signed between the two rebel groups and Khartoum on April 8. Each side has since accused the other of violations.

The rebel Justice and Equality Movement (JEM) accused the government of bombing and burning villages near Nyala, the capital of Southern Darfur state, while Annan was visiting refugees camps further north.

Khartoum blamed the rebels for the burning of the villages and said monitors were on the ground investigating the attack.

Human rights groups have accused the government of absorbing Janjaweed members into its armed forces, who then continue to loot and burn African villages. Arab tribal leaders acknowledge that some of their young men have joined government forces.

Khartoum denies any links with the Janjaweed, calling them outlaws.

Saturday's communique said Sudanese Foreign Minister Mustafa Osman Ismail would head a high-level monitoring committee formed to ensure the agreement was implemented. U.N. officials said it would hold its first meeting later on Saturday.

Sudan gave similar verbal assurances to U.S. Secretary of State Colin Powell when he visited Khartoum earlier this week.