Deployment, however, would be phased in and conditioned on security guarantees for the troops - a difficult task considering that fighting has continued in violation of the cease-fire.
Several ambassadors cautioned that the United Nations wasn't going into Congo to enforce a peace and stressed they would only deploy an actual peacekeeping mission if the Africans show a commitment to ending the war.
"The situation is so complicated that it would not only be naive but dangerous to rely on its settlement by external forces, even if these are United Nations forces," Russian Ambassador Sergey Lavrov warned.
The U.S.-drafted resolution authorizes a force of up to 5,537 personnel to be deployed to the Congo, where a rebellion launched in August 1998 has drawn in a half-dozen African nations in what U.S. Secretary of State Madeleine Albright has called Africa's first world war.
The core of the force would be 500 military observers who would monitor a cease-fire agreement signed last summer by the warring sides in Lusaka, Zambia. Congo is backed by Angola, Zimbabwe and Namibia, while the rebels who took up arms to oust President Laurent Kabila from power are supported by Rwanda and Uganda.
The remaining 5,037 U.N. troops would provide the cease-fire monitors with security and logistical support as they work with military officers from the warring sides to separate and redeploy the various forces in Congo - a country one quarter the size of the United States.
The unanimous vote culminated growing council attention and willingness to take on difficult peacekeeping operations in Africa, highlighted by U.S. Ambassador Richard Holbrooke's month-long focus on the continent in January.
Namibian Ambassador Martin Andjaba referred to the momentum from last month's Africa meetings in urging the council to stay committed to peace on the continent even after the observers are deployed.
"Over the years, the U.N. has brought peace to so many countries including my own," Andjaba said. "Expectations of the suffering masses in the (Congo) for peace in their country are therefore high and rightly so. We should not let them down."
Deputy British Ambassador Stewart Eldon, however, stressed that full deployment of the U.N. force wasn't automatic and that the situation in the Kivu region of eastern Congo, where fighting has recently flared "does not look promising."
"The fighting must stop now," he said. "International humanitarian law must be respected."
The resolution says deployment of a full-fledged peacekeeping force would depend on progress by the various factions in implementing the cease-fire agreement, which both sides have been accused of violating.
By Nicole Winfield