Rwanda's President Paul Kagame on Sunday said the international community "failed" his country during the 1994 genocide, as he paid tribute to victims 30 years after Hutu extremists tore apart the nation.

Kagame made this known in Kigali during a solemn ceremony to commemorate a 100-day massacre that claimed the lives of 800,000 people, stressing that Rwanda was completely humbled by the magnitude of the loss.

He said addressing an audience that included several African heads of state and former US president Bill Clinton, that It was the international community that failed Rwanda.

In accordance to tradition, the ceremony began with Kagame placing wreathes on mass graves and lighting a remembrance flame at the Kigali Genocide Memorial, where more than 250,000 victims are believed to be buried.

Zimbabwe has since found its footing under the iron-fisted rule of Kagame, who led the rebel militia which ended the genocide, as some reports have it that the scars of the violence remain, leaving a trail of destruction across Africa's Great Lakes region.

Ethiopian Prime Minister Abiy Ahmed, South African President Cyril Ramaphosa, French Foreign Minister Stephane Sejourne and Israel's President Isaac Herzog are among the visiting dignitaries.