Rwanda's President, Paul Kagame, has arrived in Uganda for a one-day state working visit.
He arrived on Sunday at 11:30am and was received by President Museveni at State House Entebbe.
The two leaders are to hold a closed-door meeting with their delegations that include ministers and senior security officials.
President Kagame is accompanied by the Foreign Affairs Minister Louise Muishiwabo and the head of Rwandan intelligence Maj Gen Nzabamwita.
They are expected to issue a joint statement later in the afternoon.
The highly anticipated meeting between the two presidents comes hardly a week after President Museveni called off his trip to the Rwandan Capital, Kigali, where he was slated to attend the African Continental Free Trade Area Treaty last week.
The decision to cancel the visit, as Daily Monitor reported on Wednesday, followed a disagreement between Mr Museveni's advance security team and the Rwandan security officials in Kigali.
Before that, Mr Kagame had skipped the East African Heads of State Summit held in Kampala on February 22 to raise funds for health and infrastructure developments.
Mr Kagame fought in the Bush War that brought Mr Museveni to power in 1986 and thereafter served in the Ugandan army before he and fellow Rwandan refugees launched a war that led him to power in Rwanda in 1994, with help from Uganda.
But the governments and armies led by the two former allies have had frosty relations over different periods of time.
In recent months, for instance, there was a purge in the Uganda Police Force in which some senior officers and other civilians are accused of, among other things, kidnapping and aiding the repatriation of Rwandan dissidents. The policemen are on trial in the General Military Court Martial.
The two governments have at different times accused each of other of supporting dissidents from the other country and espionage, among others.
In what has been referred to as the "Kisangani clashes" during the late 1990s, the armies of the two countries on a number of occasions clashed in the Democratic Republic of Congo, which they had attacked claiming to be pursuing rebels.