'Nothing must hamper this democratic moment, which is fundamental for our nation,' Prime Minister Bernard Cazeneuve said after an emergency security cabinet meeting on April 21.
Cazeneuve said some 50,000 police and gendarmes will be deployed to provide security during the first-round vote on April 23, with an additional 7,000 soldiers also on patrol. The election is expected to be decided in a May 7 runoff.
An attacker used an automatic weapon to shoot at police officers on the Champs-Elysees late on April 20, before being shot and killed by police. Two officers were seriously wounded.
Authorities say they have identified the gunman but have not released his name.
Reports described the attacker as a 39-year-old Frenchman who lived in a Paris suburb and had been known to security services as an Islamist radical.
Based on reporting by AFP, AP, and Reuters