The resolution, jointly proposed by the United States and Great Britain, extends the United Nations' four-year mandate that was set to expire Friday.
It calls for the U.N. Assistance Mission for Iraq, or UNAMI, to "advise, support, and assist" Iraqis on "advancing their inclusive, political dialogue and national reconciliation," Reuters reported. UNAMI will also review the Iraqi constitution, shore up internal boundaries and conduct a census.
The mandate, an expansion beyond the United Nations' original humanitarian duties, seeks to resolve internal disputes between political groups in the Iraqi government. The new responsibilities come just after almost half of the Iraqi Cabinet staged a boycott of the administration.
Zalmay Khalilzad, the U.S. ambassador to the United Nations, was optimistic that the international organization's stature would bring rival groups and nations to the negotiating table, which has proven elusive to the United States.
"This is an effort to internationalize the effort to [help] Iraqis overcome their internal difference, and to assist the neighbors by bringing them together to help Iraq rather than add to Iraq's problems," Khalilzad told the Associated Press.
Key Iraqi figures, including top Shiite cleric Grand Ayatollah Ali al-Sistani, said they were willing to discuss the country's future with the United Nations, but not with either the United States or Great Britain.
U.S. and British officials maintain they have no plans to withdraw their forces from Iraq and place the burden on the United Nations, Reuters reported.
Although U.N. Secretary-General Ban Ki-moon came out in favor of the new mandate, U.N. staff members expressed concerns this week over the mission's safety.
There are currently 65 U.N. employees in Iraq, but the new mission would increase the number to 95, according to the BBC. Many U.N. staffers in Iraq were removed following the 2003 bombing of the agency's Baghdad headquarters.
On Tuesday, the U.N. Staff Union implored the secretary-general to avoid sending additional U.N. staff to Iraq and instead requested the U.N. withdraw its entire presence.
Despite the Staff Union's appeal, U.N. spokesman Farhan Haq said Wednesday, "We intend to continue the work that is needed to fulfill our mandate," Reuters reported.