Rwanda has accused Uganda of supporting rebel groups opposed to President Paul Kagame and his government.
The Rwandan Foreign Minister, Richard Sezibera, said the the Democratic Forces for the Liberation of Rwanda (FDLR) and the Rwanda National Congress (RNC) worked from Uganda.
Ugandan Foreign Minister Sam Kutesa described the accusations as false.
Relations between the two countries are deteriorating, with Rwanda preventing Ugandan trucks from entering its territory and forbidding its citizens from entering Uganda.
Rwanda has also accused Uganda of detaining, torturing and illegally deporting its citizens.