The U.S. has told Rwanda to stop supporting rebels in eastern Congo after an annex to a U.N. report published on Friday said that top Rwandan officials have provided weapons, ammunitions and men to a new rebellion led by warlord Bosco Ntaganda, who is wanted by the International Criminal Court on war crimes charges.

A statement released on Saturday by U.S. State Department spokeswoman Victoria Nuland said that the United States “are deeply concerned about the report’s findings that Rwanda is implicated in the provision of support to Congolese rebel groups, including mutinous elements now operating as the M23 armed group.”

The U.S. has “asked Rwanda to halt and prevent the provision of such support from its territory,” the statement said.

The United States had come under pressure from the Congolese government and rights groups after the release of the annex was reportedly blocked by U.S. officials at the U.N. The move was seen as yet another cover-up for Rwandan President Paul Kagame, a U.S. ally in Africa’s Great Lakes region, who many consider a dictator maintaining his hold on power with an iron fist and an easy trigger.

Despite multiple U.N. and rights groups’ reports dating as far back as the late nineties, Rwanda has increasingly felt emboldened by the unwavering support it has received from the U.S. and the U.K., while its officials have repeatedly been implicated in political repression at home and war crimes in eastern Congo.

Rights groups have called on the United States and the United Kingdom to stop providing close to 350 million dollars in aid each year to Rwanda as long as the authorities in Kigali continue to use their tax-payers’ money to fund rebels across the border in DR Congo.

As late as it may have come, the statement from the U.S. will certainly be welcomed by many Congolese and observers of the Great Lakes region, who will see it as a sign that the U.S. will not continue to condone human rights abuses and the fueling of wars by an ally.