Uganda's president is denying support for rebels opposed to Rwanda's government as tensions rise between the two East African neighbors.

In a letter to Rwandan President Paul Kagame published on Tuesday in government-controlled media, President Yoweri Museveni says that "there is no question of Uganda supporting anti-Rwanda elements."

Museveni acknowledges he recently met with a member of a Rwandan opposition group in exile who spoke of "bad things" happening in Rwanda and who "wanted us to support them."

Rising tensions have led to fears of a possible armed conflict between the countries sharing strong ethnic and social ties.

Rwanda's government has closed a busy border crossing with Uganda, stranding traders in what Uganda describes as a trade embargo, as officials allege that anti-Kagame forces are receiving help in Uganda.