South African President Thabo Mbeki has met former rebels to try to persuade them to rejoin the Democratic Republic of Congo's government.
Refugees in Gatumba camp fled fighting in DR Congo in June
He said the talks were fruitful with one of the four transitional vice-presidents, the leader of the Rally for Congolese Democracy, Azarias Ruberwa.
Mr Ruberwa says he will announce his decision later on Wednesday. He pulled out of the government after a massacre in neighbouring Burundi.
The killing of 160 refugees prompted fears of a return to war in the region.
Mr Mbeki also met President Joseph Kabila and another former rebel leader and signed several bilateral agreements.
The BBC's Arnaud Zajtman in Kinshasa says the political crisis in DR Congo overshadowed the original agenda of Mr Mbeki's visit, which was expected to focus on economic issues.
UN Secretary-General Kofi Annan said he feared rebels from Rwanda and DR Congo had co-operated in the massacre of ethnic Tutsi refugees, which Hutu rebels in Burundi had claimed responsibility for.
Mr Annan urged the governments of Rwanda, Burundi and the DR Congo to end "the scourge of ethnic-based hostilities and abuse afflicting the people in the region".
He urged all parties not to allow the incident to revert years of progress towards peace.
The UN Security Council is scheduled to discuss the situation in Burundi later on Tuesday.
Violence between the majority Hutu tribe and the minority Tutsis has afflicted the Great Lakes region of central Africa for over a decade.
The genocide in Rwanda in 1994 and subsequent wars in Burundi and DR Congo have stemmed from it.