The statement marks a turning point for the National Front, a party that has long been connected to the antisemitism and neo-Nazi overtones of its co-founder, Mr Le Pen.
Since she took the helm in 2011, Ms Le Pen has sought to “detoxify” the party and dispel its image as a hub of right-wing extremism.
In an interview with BFM TV in Paris, Mr Le Pen defended his view that Hitler’s gas chambers were “a mere detail in the history of World War Two”.
He told the interviewer he stood by that view “because it’s the truth”.
In an interview with far-right weekly Rivarol this week, Mr Le Pen also defended Marshal Petain, the leader of France’s collaborationist Vichy regime, who was convicted of treason after the war. “I have never considered Petain a traitor”.