Military chiefs from the Democratic Republic of Congo have pledged to continue attempts to disarm rebels from Rwanda and Uganda.
UN troops remain in the east despite peace and elections
The promise came in a joint meeting in Kigali of chiefs of staff from DR Congo, Rwanda, Burundi and Uganda.
Militia groups operating in DR Congo's troubled east include extremist Hutu fighters involved in Rwanda's genocide and Uganda's Lord's Resistance Army.
Four soldiers were killed in a rebel ambush in the volatile north Kivu.
The army says rebels, suspected to be ethnic Hutus who fled to eastern DR Congo after the Rwandan genocide war in 1994, attacked a military post in the town of Matanda.
Rwanda says the Hutu FDLR rebels are regrouping and it may launch attacks.
DR Congo recently halted a seven-month military campaign against armed groups - a decision that angered Rwanda.
The BBC's Geoffrey Rutagama in Kigali said the meeting agreed to share planning and information about the operations and to regularly review any progress made.
Rwanda has twice invaded DR Congo, saying it wants to wipe out the Democratic Liberation Forces of Rwanda (FDLR).
Renegade General Laurent Nkunda also criticised the move to suspend the military onslaught against Hutu militias.
General Nkunda, who led an uprising in DR Congo's volatile North Kivu Province, in 2004 has accused the government of supporting the FDLR.
Some 165,000 civilians have fled fighting in the North Kivu province since February, when General Nkunda's army brigades launched operations against the FDLR.
Last year's historic elections were supposed to mark the end of years of conflict and mismanagement in DR Congo.