The U.N. Security Council authorized a new “intervention brigade” for Congo on Thursday with an unprecedented mandate to take military action against rebel groups to help bring peace to the country’s conflict-wracked east.

The resolution, which the council adopted unanimously, gives the brigade a mandate to carry out offensive operations alone or with Congolese army troops to neutralize and disarm armed groups.

The intervention brigade is unprecedented in U.N. peacekeeping because of its offensive mandate.

The resolution however states clearly that it would be established for one year “on an exceptional basis and without creating a precedent” to the principles of U.N. peacekeeping.

Guatemalan U.N. Ambassador Gert Rosenthal, expressed concern about getting the United Nations into “peace enforcement” which could compromise U.N. neutrality.

The resolution says the “intervention brigade” must have “a clear exit strategy.” It says the council will consider its continued presence based on its performance and whether Congo has made sufficient progress in reforming its security sector and creating a Congolese “rapid reaction force” that can take over responsibility for neutralizing armed groups and reducing the threat they pose to civilians and the government’s authority.

Russian U.N. Ambassador Vitaly Churkin, the current council president, told a news conference before the vote that the resolution will reconfigure the U.N. peacekeeping mission in Congo, “recognizing the necessity of decisively countering the destructive” violence that has left eastern Congo in turmoil since the 1994 Rwanda genocide.

The resolution, sponsored by France, the United States and Togo, would give the brigade a mandate to operate “in a robust, highly mobile and versatile manner” to ensure that armed group can’t seriously threaten government authority or the security of civilians.

The brigade will be part of the U.N. peacekeeping mission in Congo, known as MONUSCO, within its troop ceiling of 19,815. The United Nations has more than 17,700 U.N. peacekeepers and more than 1,400 international police in Congo.

The resolution extends MONUSCO’s mandate until March 31, 2014. The “intervention brigade” headquarters will be in the key eastern city of Goma. The resolution says the brigade will consist of three infantry battalions, one artillery company and one special forces and reconnaissance company. U.N. officials say it will probably include between 2,000 and 3,000 troops and the U.N. peacekeeping department will now ask U.N. member states to contribute troops.

Mineral-rich eastern Congo has been engulfed in fighting since the 1994 Rwanda genocide, in which at least 500,000 Tutsis and moderate Hutus were slaughtered by Hutu militias before a Tutsi-led rebel army took power in Rwanda. More than 1 million Rwandan Hutus fled across the border into Congo, and Rwanda has invaded Congo several times to take action against Hutu militias there.

The exploitation of Congo’s mineral resources continues to exacerbate conflict and instability on the ground.

In late February, 11 central Africa leaders and the United Nations signed an agreement to try to establish peace in eastern Congo.