The presidents of Uganda and Rwanda said they remained close allies at a weekend meeting that was clouded by rumours about Uganda having reached out to exiled Rwandan dissidents working against the Kigali regime.

President Yoweri Museveni of Uganda began a four-day visit to neighbouring Rwanda on Friday and met his Rwandan counterpart, Paul Kagame, on arrival.

Before the trip, media in both countries reported that relations were strained over reports that Ugandan security operatives had met two former senior Rwandan military officers who now opposed Kagame.

"Museveni is a friend and a brother to Rwanda," Kagame said in Kigali, where he and the Ugandan leader visited a classroom construction project.

"I am happy, truly happy," Museveni countered in Swahili after greeting residents in the Nyarugunga neighbourhood in the local Rwandan language.

The foreign ministers of both countries previously downplayed widespread reports of an ongoing diplomatic row.

"When people visit each other, it is not a sign that they are trying to solve problems," Ugandan Foreign Minister Sam Kutesa said on Rwandan radio. "It is a sign that they are friends. People don't visit each other when they are enemies."

But, according to media reports, Rwanda has continued to voice displeasure over Uganda's contact with former Rwandan general Faustin Kayumba Nyamwasa and Patrick Karegeya, Kagame's former foreign intelligence chief.

The two men, now in exile, were both top Kagame allies but have since defected from his regime. They have founded an opposition party and branded Kagame a dictator.