Nice attack: President Hollande to chair crisis talks
French President Francois Hollande is to chair crisis talks with his inner security cabinet following Thursday's attack in Nice that killed 84 people.
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.
At the meeting with the security chiefs, Mr Hollande is expected to review all available options in response to the attack.
In a televised address to the nation on Thursday night, he pledged that army reservists would be called up to help provide security across the country.
A state of emergency was in place across France since November's Paris attacks carried out by militants from the so-called Islamic State group, in which 130 people died. It had been due to end on 26 July.
- What we know about the attack
- Is freedom under threat in France?
- The jihadists of the French Riviera
- Four years of attacks in France
- 'Heartbreaking' image of victim
- Bastille Day attack in pictures
- Tears and sympathy for the victims
- Who was the attacker?
Mr Hollande said the attack was of "an undeniable terrorist nature".
He warned that the battle against terrorism would be long, as France faced an enemy "that will continue to attack those people and those countries that count liberty as an essential value".
"We will overcome the suffering because we are a united France," he said.
Paris prosecutor Francois Molins said that no group had admitted carrying out the attack but that it bore the hallmarks of jihadist terrorism.
Lahouaiej-Bouhlel was known to the police as a petty criminal, but was "totally unknown to intelligence services... and was never flagged for signs of radicalisation," the prosecutor added.
Interior Minister Bernard Cazeneuve said he could not confirm links to jihadism, but Prime Minister Manuel Valls told France 2 television that Lahouaiej-Bouhlel was a "terrorist without doubt linked to radical Islamism in one way or another".
Some 30,000 people were on the Promenade des Anglais at the time of the attack, officials said.
Residents of Nice and foreign tourists were killed, among them four French citizens, three Algerians, a teacher and two schoolchildren from Germany, three Tunisians, two Swiss, two Americans, a Ukrainian, an Armenian and a Russian.
The son of Fatima Charrihi, a 60-year-old Nice resident from Morocco, said she was the first to die. He said she "practised Islam in the proper way. A real Islam, not the terrorists' version".
Tunisian security sources said Lahouaiej-Bouhlel came from the Tunisian town of Msaken. He visited Tunisia frequently, the last time eight months ago.
Justice Minister Jean-Jacques Urvoas said the suspect had been given a suspended sentence earlier this year following a confrontation with another driver but this was his only conviction.
Residents of his apartment building said he was a loner who did not respond when they said hello.
Timeline of terror: France's deadliest Islamist attacks
- June 2016 - man claiming allegiance to so-called Islamic State kills two police officials in Magnanville, near Paris
- November 2015 - multiple attacks on Paris by seven gunmen and suicide bombers kill 130 people and injure more than 350 in the deadliest terror attack in French history
- June 2015 - man with suspected links to Islamist radicals decapitates his boss after ramming his car into an area containing flammable liquids at factory in Lyon
- January 2015 - three days of attacks by gunmen in Paris leave 17 people dead, starting with an attack on the office of satirical magazine Charlie Hebdo and ending in two sieges
- March 2012 - a gunman kills seven in Toulouse and Montauban, including a teacher and three children at a Jewish school