Rwandan President Paul Kagame has accused French people of "direct involvement" in the 1994 genocide.
Kagame denies ordering the shooting down of the Rwandan president's plane in 1994
He told the French state-owned RFI
radio that they provided weapons and training, and gave orders to those who
killed some 800,000 people.
He said the "French elements" were acting on government orders.
The president was speaking a week after a French daily reported a police report that blamed him for a rocket attack that precipitated the massacre.
"Sooner or later they will have to account for their actions, either before a French court or the international court," Mr Kagame said.
The report - extracts of which appeared in Le Monde - concludes that Mr Kagame gave direct orders for the rocket attack on then President Juvenal Habyarimana's plane.
He has denied the claim.
Mr Kagame was head of the mainly-Tutsi rebel Rwandan Patriotic Front (RPF) at the time.
Burundi's then President Cyprien Ntaryamira was also killed in the rocket attack.
Le Monde said the accusation against Mr Kagame is contained in a 220-page report drawn up by police acting for France's leading anti-terrorist judge, Jean-Louis Bruguiere.
The police are investigating the deaths of several French citizens on the plane.