Violence in eastern DRC has intensified since rebel Gen. Bosco Ntaganda, wanted by the International Criminal Court for war crimes, waged mutiny in April.
Fidele Sarassoro, U.N. humanitarian coordinator for DRC, said the level of violence is creating a chaotic situation for civilians in the region.
"We call on all parties to the conflict to respect human rights and international law and to spare civilians from the violence," he said in a statement.
The United Nations this week said it estimated that more than 20,000 people have fled the fighting in DRC to neighboring Rwanda and Uganda.
Ntaganda is suspected of conscripting child soldiers into the fighting. Some of his associates are tied to the Democratic Forces for the Liberation of Rwanda, a militant group tied to the Rwanda genocide in 1994.
"It is essential that this crisis be resolved quickly because families need peace and protection," Sarassoro said.