The UN Security Council voted unanimously to extend the mandate of the 16,700-member UN peacekeeping mission in Congo for a year and add 300 troops. The small addition Friday is far less than the 2,580 troops that Secretary-General Kofi Annan requested. To underscore that the 300 troops were a temporary addition, the council asked Annan to reduce the force by that number by July at the latest. Annan had urged the council to bolster the mission to help secure some of the most troubled pockets of the country ahead of elections set for next year. But some council members, led by the United States, contend the peacekeeping force is already the largest in the UN system and shouldn't get any bigger.