Retired Canadian general Roméo Dallaire has completed his testimony at the international criminal tribunal set up to prosecute crimes stemming from Rwanda's 1994 genocide.

Dallaire, who was commander of United Nations forces in Rwanda when an estimated 800,000 mostly minority Tutsis were killed, was testifying at the trial of four former military officers accused of orchestrating the genocide.

Under cross-examination on Friday, Dallaire described his attempts to persuade the extremist Hutu government and the Tutsi rebels to stop violating peace accords signed a year earlier.

Defence lawyers have repeatedly challenged Dallaire's credibility, questioning his recollection of events, his knowledge of Rwanda and his mental state.

After returning to Canada from Rwanda, Dallaire suffered from a much-publicized nervous breakdown.