French Interior Minister says authorities will do everything possible to ensure security at Sunday's march in Pairs to show unity against extremists.
2,400 riot police officers will be deployed across the region.
Bernard Cazeneuve says the government is maintaining its terror alert at the highest level in the Paris region.
"One-hundred-and-fifty policemen will be in charge of high profile participants, monitoring the public. Twenty anti-criminality teams will be in charge of detecting individuals with potential threat. Snipers will be positioned on the roofs all along the way."
Two dozen world leaders, including German Chancellor Angela Merkel and British Prime Minister David Cameron, are expected to join the event.
On Saturday, around 700,000 peaceful protesters took part in marches across the country to commemorate the victim of violence in the past week.
Most of the marches were held in silence with some protesters holding banners that read "unity".
The family of a French Muslim police officer killed in the Pairs newspaper attack also spoke out against racism.
Malek Merabet is the policeman's brother.
"To all the racists, Islamophobes and anti-Semites, extremists must not be confused with Muslims. I'd like to bring up one more point, stop confusing things, stop starting wars, burning mosques or synagogues: you are dealing with human beings here."
Altogether 17 victims have died along with the three hostage-takers since the shooting in offices of satirical newspaper Charlie Hebdo on Wednesday.
One of the hostage takers said the attacks are commissioned by Al-Qaida Yemen.
Police are now hunting for accomplices of the three gunmen.
