The presidents of Rwanda and the Democratic Republic Congo will take part in a regional summit in Uganda to agree on a neutral force tasked with policing their border and neutralising rebel groups, officials said.
Ugandan President Yoweri Museveni will from Tuesday host the two-day summit of 11-member International Conference on the Great Lakes Region (ICGLR) at a lakeside resort outside the capital Kampala.
A three-month-old uprising by M23 rebels in eastern DR Congo has killed an unknown number of people and displaced around 280,000. Twenty thousand UN peacekeepers are already based there.
Kigali confirmed on Monday that Rwanda's Paul Kagame would attend the summit while airport sources in Kinshasa said Congolese President Joseph Kabila was already on his way there.
The UN will also dispatch a representative to the summit, which aims to defuse mounting tensions between Rwanda and DR Congo, who have traded accusations of supporting each other's rebels.
Kinshasa charges that Rwanda is arming the M23 mutiny which has battled regular forces in the eastern DR Congo since May while Kigali accuses its neighbour of plotting attacks with Rwandan Hutu rebels based in the same region.
A UN report published in June said there was ample evidence that Kigali was actively involved in the M23 rebellion led by a renegade Congolese general who is wanted by the International Criminal Court for crimes against humanity.
Experts say the latest turmoil is the result of an ongoing battle for control of the mineral-rich region, in which Rwanda has long been accused of maintaining a stake by using Congolese militias as proxies.
Rwandan President Paul Kagame told the AFP news agency in mid-July that both sides had agreed "in principle" to accept a neutral force.
A meeting of regional defence ministers held in Khartoum last week was supposed to hammer out some of the details of the force, as Kigali and Kinshasa hold divergent views of which troops would be neutral.
Kinshasa has said it favours using MONUSCO, the 19,000-strong UN stabilisation force deployed in the DR Congo.
Kigali, while it has not issued any outright public refusal of MONUSCO, argues that the UN force is anything but neutral.
Regional foreign ministers holding preparatory meetings behind closed doors on Monday were discussing at least three types of force, according to documents available at the venue.
One option would see the region's states contribute troops and funds. The African Union has said it is ready to contribute to such a force.
A second option is "an international and regional force incorporated into MONUSCO" and including a beefed up mandate as MONUSCO's current mandate is limited to the protection of civilians.
A third idea is an "interim MONUSCO force" but the document did not specify if this would be in addition to the "international and regional force."
Even if a compromise is reached, the troops still need to be capable of routing some of the most battle-hardened fighters in the region, be it the M-23 or the Rwandan FDLR rebels.
The 11-nation ICGLR comprises Angola, Burundi, Central African Republic, Republic of Congo, Democratic Republic of Congo, Kenya, Uganda, Rwanda, Sudan, Tanzania and Zambia.