PARIS -- French President Francois Hollande announced Thursday that he would not seek a second term in next year's presidential election, saying he hoped to give his Socialist party a chance to win "against conservatism and extremism" by stepping aside.

"I have decided not to be a candidate in the presidential election," Hollande said in a sombre address on French television that recapped his achievements since taking office in 2012.

The 62-year-old president -- the country's least popular leader since World War II -- said he was "conscious of the risks" his lack of support posed to a successful candidacy.

"What's at stake is not a person, it's the country's future," he said.

The Socialist party has been deeply divided over Hollande's policies, with rebels within the party openly criticizing his pro-business strategy and calling for more left-leaning policies.

Two of his former colleagues, former Economy Minister Arnaud Montebourg and former Education Minister Benoit Hamon, already have announced they would run in next month's Socialist primary, alongside other low-profile candidates.

Hollande repeatedly had said he would seek re-election only if he were able to curb the unemployment rate in France, which for years has hovered around 10 per cent. The latest figures showed a slight decrease in the jobless numbers, but didn't seem to quell the criticism.

Hollande was expected to say in the coming weeks whether he would seek to run again. His announcement Thursday came just a few days after his No. 2, Prime Minister Manuel Valls, said he was "ready" to compete in the Socialist primary.

Valls praised Hollande "tough, mature, serious choice" without saying if he would run for presidency, in a written statement on Thursday night.

"That's the choice of a statesman," he said.

Valls said Hollande had led France with a "constant concern" for the protection of the French people, in an implicit reference to several attacks by Islamic extremists in the country in recent years.

"I want to tell Francois Hollande my emotion, my respect, my loyalty and my affection," he added.

In his address Hollande avoided saying if he would support Valls -- or any other candidate.

The president's office -- denying rumours of an internal battle -- said the two men had their weekly working lunch on Monday at the Elysee Palace in a "cordial and studious atmosphere."

An at times emotional Hollande said during his televised remarks that he was standing aside so the Socialists would have a better chance of holding on to power, which he said was for the "interest of the country."

Whichever candidate Socialist voters choose in January will face former Prime Minister Francois Fillon, who won France's first-ever conservative presidential primary on Sunday. Fillon has promised drastic free-market reforms, along with a crackdown on immigration and Islamic extremism.

Marine Le Pen, leader of the far-right National Front party, is expected to be a major competitor in the two-round presidential election in April and May.

Centrist Emmanuel Macron, the former economy minister under Hollande, also is seeking the presidency in the general election scheduled for April-May, but has decided not to take part into the Socialist primary.

With a nod to the 2017 field, Hollande called on a collective reaction of "all progressives who must unite in these circumstances."

"As a life-long Socialist, I cannot allow the dissipation of the left, its breaking up, because it would rid us of any hope of winning in the face of conservatism or, worse still, extremism," Hollande said.