Prime Minister Manuel Valls says the French justice system has failed in connection with the killing of a priest in a church in Normandy on Tuesday.
In a newspaper interview, he criticised the fact that one of the two attackers had been released with an electronic tag pending trial on terror charges.
He said the release had been decided by independent judges, not his government.
Mr Valls has faced criticism over the attack near Rouen, and the killing of 84 people by another jihadist in Nice.
Adel Kermiche, one of the two teenagers who attacked the church in Saint-Etienne-du-Rouvray on Tuesday, had been arrested after being caught trying to go to Syria last year.
However he was released with a monitoring tag earlier this year, despite prosecutors’ call for his continued detention.