In a TV address the French president said over-65s will need COVID booster jabs to extend their health passes from mid-December.
Emmanuel Macron has announced new measures to encourage older people to come forward for a third vaccination dose against the coronavirus, in a bid to stem a rise in the number of infections and hospitalisations in France.
In a TV address, the French president said that from mid-December, a booster jab will be needed in order for people aged over 65 to have their health passes extended.
Since September, one-dose booster jabs have been available for the elderly, the most vulnerable, and care and health workers, but take-up has been slow. As of last weekend only 3.4 million from 7.7 million who are eligible had received third doses.
The third vaccination dose is necessary to offset the waning efficiency over time of all vaccines against COVID-19.
"We need to speed things up," Macron said in his address. "From December 15, you will need proof of a booster to extend the validity of your health pass."
Since the summer, the "pass sanitaire" has been necessary for entry to bars, restaurants and other venues. The health pass shows proof of full vaccination status, a recent negative COVID-19 test, or recovery from the disease.
Macron added that 50 to 64-year-olds will be eligible for a booster dose from the beginning of December, expressing concern at the resurgence of coronavirus cases which he said had risen by 40% in a week.
"More than 80% of people in intensive care are aged over 50, that's why a recall campaign will be launched from the start of December for our citizens, aged between 50 and 64," the president said.
"We have alerted the scientific authorities so that they can indicate to us in the coming days the practical methods and deadlines to follow," he added.
Describing the rising case numbers as an "alert signal" to the country, the president said the fifth wave of COVID-19 had begun in Europe and urged everyone to get vaccinated -- citing the six million people in France still to get the jab.
The French president also used his address to announce that France is to build new nuclear reactors for the first time in decades, as well as develop renewable energy.
He added that he looked forward to France taking the six-month EU presidency from January, to work with Europe in tackling the world's challenges.
Citing "an unprecedented convergence of crises", from the pandemic to terrorism, he acknowledged people's concerns and anger. But he said, "don't be afraid", urging people to believe in France and its values and not cede to dogma or nationalism.
Macron's address comes five months before the first round of the 2022 presidential election.