Interior Minister Bernard Cazeneuve said police gendarmes and military have been deployed days after Islamist militants attacked Paris.
He vowed to boost funding for police equipment, which he said had fallen by 17% in 2007-12.
The interior minister added that 128 raids on suspected Islamist militants had been carried out overnight on Monday to Tuesday.
More than 160 raids were made earlier on Monday, with 23 people arrested and dozens of weapons seized.
After the French Prime Minister, Manuel Valls, warned that new terror attacks were being planned in France and other European countries, Belgium’s government raised its terror threat level because of the failure so far to arrest one of the suspects, Brussels-born Salah Abdeslam, causing Tuesday’s football match between the national team and Spain to be cancelled.
There has been a huge manhunt for Abdeslam since Monday.
The measures came as US Secretary of State, John Kerry, visited Paris.
Speaking on Monday outside the US embassy, he described IS as “psychopathic monsters”.
He called France America’s oldest friend and first ally, and said the only response to the attacks must be a fierce sense of solidarity.
French aircraft have, however, started retaliatory attacks in Raqqa, the stronghold of the Islamic State group in Syria, which claimed responsibility for Friday’s attacks.
Mr Valls said that France was dealing with a “terrorist army”, rather than a single terrorist group.