The UN Security Council authorised on Tuesday up to 26,000 troops and police for Darfur in an effort to protect civilians and quell violence in Sudan's vast arid western region.
Expected to cost more than $2 billion (1 billion pounds) in the first year, the combined United Nations-African Union operation aims to quell violence in Darfur, where more than 2.1 million people have been driven into camps and an estimated 200,000 have died over the last four years.
UN Secretary-General Ban Ki-moon described the resolution as "historic" and urged member states to offer "capable" troops quickly.
The resolution, number 1769, invokes Chapter 7 of the UN Charter, under which the United Nations can authorise force. The measure allows the use of force to be used for self defence, to ensure the free movement of humanitarian workers and to protect civilians under attack.
But the resolution, which has been watered down several times, no longer allows the new force to seize and dispose of illegal arms. Now they can only monitor such weapons.
Gone also is a threat of future sanctions, but Prime Minister Gordon Brown warned on Tuesday that "if any party blocks progress and the killings continue, I and others will redouble our efforts to impose further sanctions.
"The plan for Darfur from now on is to achieve a cease-fire, including an end to aerial bombings of civilians; drive forward peace talks ... and, as peace is established, offer to begin to invest in recovery and reconstruction," he said on a visit to the United Nations.
Britain and France are the main sponsors of the resolution.
