The leader of the Democratic Republic of Congo and senior ministers from Rwanda and Uganda have agreed to try to end regional fighting.
Peace has led to a power-sharing government in DR Congo
In a meeting at the United Nations in New York, they promised to stop interfering in each others' affairs.
They also pledged to end arms shipments to eastern DR Congo, where clashes continue despite a peace deal.
UN Secretary-General Kofi Annan welcomed the accord, but said more was needed: "The job is not done. It is not even close to done." he told them.
A transitional government including former rebel leaders has been installed in the capital, Kinshasa, since the signing of the peace agreement.
An estimated three million people died during the war which pulled in at least six other African armies along with numerous rebel groups and militias.
The presidents of Burundi and Mozambique also took part in the meeting,