The influx of French staff comes after Italy refused to let a private humanitarian rescue ship dock in one of its ports.
Border controls between France and Italy have been tightened after a diplomatic stand-off over migrants.
France has sent 500 extra officers to carry out border checks at ten different Italian border crossing points.
From Sunday, lines formed at border crossings as police stopped ‘nearly every car’ and searched many.
French authorities have promised “serious” passport checks for everyone attempting to cross between the countries.
What is the latest advice for travelling between by France and Italy by car?
The beefed-up border security means that transit over the border into France may take longer than usual. Travellers should consider setting off earlier than planned, and be prepared to wait in a queue of cars.
Why is France beefing up border controls with Italy?
The stand-off comes after a diplomatic row over migrants.
Every year, thousands of migrants attempt to cross between North Africa and southern Italy. In the first eight months of 2022, 1,200 of these people tragically drowned.
Private humanitarian rescue ships patrol the waters between the continents, looking for tiny boats.
Last month, the Ocean Viking charity rescue ship saved 234 migrants, including 57 children, as they tried to reach Catania in Sicily.
But Italy refused to allow the ship to dock for three weeks, forcing the vessel to sail to France.
The French government called Italy “irresponsible” and “inhumane” for not aiding the ship, accusing the right wing Italian government of a “breach of trust.”
The new Italian prime minister Giorgia Meloni was elected promising to stop the flow of migrants between Africa and Italy.
But in response to the dispute, France has decided to freeze a plan to take 3,500 asylum seekers currently in Italy. This plan was part of a European migrant-sharing “solidarity mechanism.”
"Italy is not keeping a commitment that is fundamental to the European solidarity mechanism," French government spokesperson Olivier Veran said on Sunday.