The outgoing president has also scheduled an emergency security cabinet meeting on Friday.
Mr Cazenueve said the government and security forces were fully mobilised after the fatal shooting of a policeman in Paris, with only days to go until Sunday's national poll.
The gunman who shot and killed a police officer on the Champs-Elysees in Paris was detained in February for threatening police and then freed.
Authorities are trying to determine whether "one or more people" might have helped the attacker, Interior Ministry spokesman Pierre-Henry Brandet said.
One of the key questions was if, and how, the attack that killed one police officer and wounded three other people might impact voting intentions.
Security has been tight in France, coming just days before the first round of the presidential election on Sunday.
It is not certain whether the attack is terrorist related but France's President Francois Hollande says the Champs- Elysees shooting is "terrorist in nature".More news: U.S. transportation sector adds another 3500 jobs in March
The 48-year-old National Front leader called for France to "immediately" take back control of its borders from the European Union and deport all foreigners on a terror watchlist. Security is high preceding the vote after police said they arrested two men Tuesday in what they described as a thwarted terror attack.
The Paris prosecutor's office leading the investigation has said a pump-action shotgun and knives were found in the gunman's vehicle.
The prosecutor added that the man had nothing to do with the attack.
The global model, who appeared on Page 3 of the Daily Star on February 28, says she saw a rush of police and ambulances stop close by her.
As soon as he shot at the policemen, the gunman made no attempt to run and hide.
ISIS has since claimed the attack, but the French authorities say they don't have a connection of the shooter to ISIS yet.
Islamic State claimed it was responsible for the attack and named Abu Yusuf al Beljiki as the attacker - though it is believed this could be a pseudonym for Cheurfi.More news: Facebook Introduces Augmented Reality Camera Effects Developer Platform
Conservative contender Francois Fillon, who has campaigned against "Islamic totalitarianism", said he was cancelling his planned campaign stops on Friday.
Meanwhile, French police have taken into custody three family members of the gunman killed in Thursday's shootout the Champs Elysee, a legal source said on Friday. "We have to be strong and we have to be vigilant".
Belgium first came under the spotlight after investigators said several men based in Brussels plotted and carried out the Paris attacks on November 13, 2015, killing 130 people and wounding hundreds more.
France's Prime Minister Bernard Cazeneuve paid tribute to the officer and tweeted that his thoughts are with the family.
A female foreign tourist also was wounded, Molins said.
According to BFMTV news channel's sources, the killer was known to the security services and had talked of wanting to kill police officers on the Telegram messaging service.
Presidential candidates Emmanuel Macron and Marine Le Pen reacted on Friday morning to the previous evening's attack on the Champs Elysees.More news: Joe Pavelski scores fastest playoff goal in Sharks history
Speaking in Washington during a news conference with Italian Prime Minister Paolo Gentiloni, U.S. President Donald Trump said the shooting "looks like another terrorist attack" and sent condolences to France.
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