United Nations ? The U.N. Security Council voted unanimously Friday to establish a peacekeeping mission of up to 15,000 troops for Liberia, where a smaller West African peace force has helped stabilize the capital, but fighting persists in the countryside.

The U.S.-backed resolution, introduced Monday, authorizes the deployment of up to 1,115 civilian police officers, 250 military observers and 160 staff officers, in addition to the troops, for a 12-month period. They are to take over from the 3,250-strong Nigerian-led West African force on Oct. 1.

The resolution authorizes the new peacekeeping force to monitor the cease-fire and investigate violations, monitor the disengagement of all forces, and work with others to develop a plan within 30 days to disarm, demobilize and reintegrate combatants.

It gives the U.N. force a broad mandate to help implement a June 17 cease-fire agreement, assist Liberia’s new transitional government, facilitate the delivery of humanitarian aid, protect U.N. staff and disarm combatants.

The council resolution also “demands the Liberian parties cease hostilities throughout Liberia” and that neighboring states end any support to armed groups operating in the country, which has seen 14 years of nearly continuous conflict.

In August, the council authorized the West African force that has succeeded in bringing calm to Liberia’s capital after nearly three months of fighting between forces loyal to warlord-turned-President Charles Taylor and rebels battling since 1999 to oust him.

The fighting has killed more than 1,000 civilians.

Taylor went into exile in Nigeria on Aug. 11, but fighting has continued in the countryside.

A new administration is scheduled to be installed Oct. 14, leading to democratic elections in 2005.

On Friday, the 15-member Security Council also voted unanimously to extend the U.N. mission to Sierra Leone, which borders Liberia, for six months from Sept. 30. The 13,000-strong mission is currently the world body’s largest. A Bangladeshi battalion of about 850 troops is to be redeployed from Sierra Leone to Liberia on Sept. 23.

The resolution also urges Sierra Leone’s government to strengthen its control over the diamond trade, which had been used by rebel factions to finance the country’s decade-long war, and urges member states to contribute funds to the U.N.-backed war crimes court, which faces a “precarious financial situation.”

The war-crimes court has indicted Taylor as a primary culprit in Sierra Leone’s war.