Reforming France's costly and complicated pension system was a key plank of Macron's election platform when he came to power in 2017.

But his initial proposals provoked weeks of protests and transport strikes just before the COVID-19 pandemic hit. Macron put the initiative on hold as he ordered France into lockdown in early 2020.

"We need to work longer," he said in a televised speech, adding that the reform would be implemented by the end of the summer.

Macron, who won a second presidential mandate in April but lost his outright majority in parliament in June - making it tougher for him to implement reforms - urged the French to be united.

Macron has long made it clear he wants to raise the retirement age - but this has already met fierce resistance from unions and, according to polls, is deeply unpopular with the public.

In his New Year speech, he also urged the French to continue with energy savings, saying this was one way for the country to avoid electricity cuts, as the war drags on in Ukraine.