The French government has announced that it is pulling out of the 20th anniversary commemorations on Monday for the Rwandan genocide.
The decision follows an accusation by the Rwandan President, Paul Kagame, that France participated in the mass killings in 1994.
Mr Kagame has previously made similar allegations, which France has denied.
The French foreign ministry said the remarks went against reconciliation efforts between the two countries.
French Justice Minister Christiane Taubira has cancelled her plans to attend the events in Kigali on Monday, foreign ministry spokesman Romain Nadal says.
Speaking to the French-language weekly news magazine Jeune Afrique, Mr Kagame denounced the “direct role of Belgium and France in the political preparation for the genocide”. Rwanda was a Belgian colony until 1962.
In the interview, carried out on 27 March, Mr Kagame is quoted as saying that, 20 years on, “the only plausible reproach in [France’s] eyes is in not having done enough to save lives during the genocide”.
It comes as Rwanda prepares to mark the 20th anniversary of the atrocities that claimed at least 800,000 lives – mostly ethnic Tutsis and moderate Hutus – over a period of about 100 days.
The violence was triggered by the death of President Juvenal Habyarimana, an ethnic Hutu who was killed in a plane crash on 6 April 1994.
It came to an end after Mr Kagame’s Rwandan Patriotic Front (RPF) – a Tutsi-led rebel group – defeated government troops in July that year.
His party still controls the government and has long accused France – an ally of Mr Habyarimana’s government at the time – of aiding the genocide.
In recent years there has been a thaw in relations between the two countries, with a visit by Mr Kagame to Paris in 2011 and the establishment by France of a genocide investigation unit.
France has acknowledged that serious errors were made during the genocide in Rwanda.
A Rwandan commission in 2008 said France was aware of preparations for the genocide and helped train ethnic Hutu militias who participated in killings.
Paris said its forces helped protect civilians as part of a UN-mandated intervention in Rwanda. But Mr Kagame said French troops had protected the militias carrying out the killings.