COVID-19 was spreading at parties and private gatherings, the president said on Wednesday, and action was needed in Paris and eight other big French cities to slow infection rates or risk hospitals being overwhelmed.

Macron said the curfews were to temporarily halt "the parties, the moments of conviviality where there are 50 or 60 people, festive evenings because, unfortunately, these are vectors for the acceleration of the disease."

Macron announced the curfews, which will take effect from Saturday and run nightly from 9 pm to 6 am, hours after the government declared a new state of emergency.

The curfews will last an initial four weeks but Macron says the government will seek a two-week extension from parliament, meaning the measures will be in place until December 1.

"It means that we won't go to restaurants after 9 pm, we won't go round to a friend's place, we won't go out partying," the president said.

France, like other European countries, is grappling with how to slow the virus and ease pressure on a once-again strained healthcare system while keeping its 2.3 trillion euro ($A3.78) trillion) economy open and protecting jobs.

On Wednesday it reported 22,591 new cases, the third time in six days the daily COVID tally has gone beyond the 20,000 threshold.

The virus has killed more than 32,000 in France.

The curfew applies to the Paris region, Marseille, Toulouse, Grenoble, Montpellier, Rouen, Lyon, Saint-Etienne and Lille. The cities have a combined population of about 20 million people.

Macron said France faced a worrying situation.

"We have to adopt stricter measures in order to completely restore control," the president continued.

Essential trips during curfew would still be allowed, he said. There would be no restrictions on public transport, and people would still be able to travel between regions without restrictions.

Anyone violating the curfews will be fined 135 euros.

Macron said the goal was to reduce the current rate of 20,000 new cases per day to around 3000 and sharply reduce the burden on intensive care units in hospitals.

The French government previously declared a state of emergency in March, when hospitalisations caused by the pandemic were near their peak.

That time, authorities used extra powers to put France under lockdown except for essential work, buying food or taking one hour of daily exercise.

Another national lockdown was not envisaged, said Macron.

"We'll get through this if we stick together," the president said.

But the move is likely to infuriate France's already-battered hospitality industry, reeling from the three-month spring confinement and a more recent government-ordered shutdown of bars in virus hotspots.

Australian Associated Press