"We want to bring the French nation together".
Speaking in Nice on Friday, President Hollande said that approximately 50 of the injured are "between life and death".
The first minister has said that Scotland stands in solidarity with France following the attack.
The attacker wanted to "harm the very idea of national unity", he said, adding solemnly that France is having to learn to live with regular attacks.
According to some reports, the terrorist - a 31-year-old French-Tunisian man - may be connected to Islamic State, though no organization has claimed responsibility for the attack yet, RIA Novosti reported.
A photograph showed the front of the truck riddled with bullet holes and badly damaged, with burst tyres.
Sunni Islam's leading centre of learning, Al-Azhar, said the "vile terrorist attack" contradicted Islam and called for "uniting efforts to defeat terrorism and rid the world of its evil".
"A person jumped onto the truck to try to stop it", Ciotti told Europe 1 radio. The Paris prosecutor's office opened an investigation for "murder and attempted murder in an organized group linked to a terrorist enterprise".
The incident comes as France was breathing a sigh of relief after successfully hosting the month-long Euro 2016 football championship, which passed off without incident. "They had to stay there for a couple of hours, but people wouldn't even come out - they were so frightened - until the police came and said it was OK to come out", he said.
"A fraction of a second later, an enormous white truck came along at a insane speed, turning the wheel to mow down the maximum number of people", he said. "I grabbed my son, I felt like shielding him, protecting him from seeing that. Heard noises, cries that I will never forget". A pink girl's bicycle was overturned by the side of the road.
The day commemorates the Storming of the Bastille on 14 July 1789, an important event in Paris in the French Revolution, which had begun two days earlier, as well as the Fête de la Fédération which celebrated the unity of the French people on the same day in 1790. "My daughter. I don't know", he said, still in a state of shock.
France has long known it is a top target for the Islamic State group. "I am the only one who went".
"It is bad to see that dozens of people have again been affected by a deadly attack, particularly as this was on a day of national celebration in France".