Regional leaders have failed to agree at a summit in Uganda on deploying a new force to tackle militia groups in eastern Democratic Republic of Congo.
“We will meet again in four weeks,” Ugandan President Yoweri Museveni said, the AFP news agency reports.
Last month, the African Union called for a force to be established within weeks, as conflict escalated.
Meanwhile, gunmen have attacked the airport in the southern Congolese mining city of Lubumbashi.
At least one soldier was killed in a shoot-out that lasted several hours.
The government blamed a similar attack on the airport last year on armed men linked to secessionists in the south-east.
In the separate conflict in eastern DR Congo, nearly 250,000 people have been displaced since April following a rebellion launched by renegade General Bosco Ntaganda, the UN says.
Gen Ntaganda’s M23 rebel movement – which has been active in the provinces of North Kivu and South Kivu – is accused by the UN and DR Congo government of receiving military backing from Rwanda.
The leaders of DR Congo and Rwanda – Joseph Kabila and Paul Kagame respectively – attended the summit in Uganda in an effort to resolve the conflict.
But there was no clear agreement on the deployment of a force or to take other measures to achieve peace, correspondents say.
Instead, a post-summit statement issued by the leaders said defence ministers should come up with “actionable steps to ensure that fighting stops completely” and provide details on the “operationalisation of the neutral international force”.
The UN has more than 20,000 troops in DR Congo and the AU says it should be bolstered by a regional force.
Last month, Mr Kagame told AFP that he and Mr Kabila agreed “in principle” on a neutral force.
Eastern DR Congo has been plagued by fighting since 1994, when more than a million ethnic Hutus crossed the border into DR Congo following the Rwandan genocide, in which some 800,000 ethnic Tutsis and moderate Hutus were killed.
Rwanda has since twice invaded its much larger neighbour, saying it was trying to take action against Hutu rebels based in DR Congo.