The U.N. Security Council imposed sanctions on leaders of the March 23 rebel movement in Democratic Republic of Congo and the Democratic Forces for the Liberation of Rwanda, known by its French initials FLDR.
M23 forces, which mutinied in early 2011, captured the capital of North Kivu province last month but later withdrew. Rwanda is accused of backing M23 rebels, though it denies the allegations.
U.S. Ambassador to the United Nations Susan Rice said the United States was concerned about the security situation in eastern DRC.
"For years, the FDLR has committed atrocities against civilians and remains a threat to the stability of North and South Kivu (provinces)," said Rice in a statement. "(The) action against the FDLR is a critical step toward ending impunity and advancing peace."
U.N. officials have said rebel forces remained in the area, noting sexual violence was carried out against the civilian population in the area.
"The international community remains deeply concerned about the rapidly deteriorating security and humanitarian crisis in eastern DRC due to ongoing military activities of the M23," Rice said.