The U.N. Security Council voted unanimously Tuesday to extend the U.S.-led multinational force in Iraq for one year, a move that Iraq's prime minister said would be his nation's "final request" for help.

Authorization for the 160,000-strong multinational force was extended until the end of 2008 because "the threat in Iraq continues to constitute a threat to international peace and security," according to the resolution.

U.S. Ambassador Zalmay Khalilzad formally introduced the resolution Tuesday afternoon and soon after the council met to approve it.