KINSHASA, Congo (AP) — Congo's president accused Rwanda of backing a new rebellion in Congo's east and called their support an "open secret".

President Joseph Kabila spoke to journalists late Saturday in a rare appearance and said that the Government will investigate accusations that Uganda may also be backing the M23 rebellion in the east, though the country said it was not involved.

The uprising has brought the worst violence in years to the already volatile Congo. It has forced more than 260,000 people from their homes in the past three months. And it is draining the resources of an already overstretched US$1.5 billion a year UN peacekeeping mission in Congo.

"Regarding the involvement of Uganda, Kampala's explanation is that they have nothing to do with it," Kabila said, adding that Rwanda's involvement is an "open secret. A UN report clearly shows that M23 is backed by Rwanda".

A report by UN experts last month accused Rwanda of helping create, arm and support the M23 rebel movement in violation of UN sanctions. Rwanda denies the charges.

Rwanda has come under increasing pressure, however, to halt the alleged support with The Netherlands, US and Germany suspending some aid and Britain delaying a payment for budgetary support. While the amounts involved are small, the actions are considered a major rebuke of Rwanda, a darling of Western donors dependent on aid for nearly half its budget.

Congo's president admitted the army has lost some territories to the rebels, but said they will recover other localities and the major objective is to restore lasting peace in the east.

"There are several possible solutions to end the crisis, political, diplomatic or military," he said.