Mr Hollande, who says the attack was a terrorist act, has already extended a state of emergency by three months.
On Thursday, a lorry driver ploughed through a crowd marking Bastille Day on Nice's Promenade des Anglais.
The driver was later shot dead by police. He was identified as Tunisian Mohamed Lahouaiej-Bouhlel, 31.
Prosecutors said he had driven the lorry 2km (1.2 miles) along the famous promenade, zigzagging and targeting people.
Ten of the dead were children. Some 202 people were injured; 52 are critical, of whom 25 are on life support.
