Japan is on the brink of not being able to function as a society as its plummeting birthrate reaches crisis point, the country’s prime minister has warned.

Prime Minister Fumio Kishida said it was “now or never” for one of the world’s oldest societies, and he has vowed to take urgent steps.

Mr Kishida sounded the alarm in a policy speech marking the opening of this year’s parliamentary session.

Japan has a population of 125 million and researchers have predicted that would fall to 53 million by the end of the century.

Births plunged to a new record low last year, dropping to less than 800,000 for the first time — a watershed moment that came eight years earlier than the government had expected.

The country’s median age is 49 — the highest in the world behind only the tiny city-state of Monaco.

“Our nation is on the cusp of whether it can maintain its societal functions,” Mr Kishida told parliament.

“It is now or never when it comes to policies regarding births and child-rearing.

“It is an issue that simply cannot wait any longer.”

The Japanese government recently offered to pay families to move out of Tokyo in an effort to boost the plummeting birth rate. Photo: Getty

Japan has in recent years been trying to encourage its people to have more children with promises of cash bonuses and better benefits.

But it remains one of the most expensive places in the world to raise a child, according to surveys.

Other contributing factors include more women in the workforce and greater access to contraception.

Japan also has limited immigration, with only 3 per cent of its population foreign-born, compared to 27.6 per cent in Australia according to the 2021 Census.

Mr Kishida said he would submit plans to double the budget for child-related policies by June and set up a new Children and Families government agency in April to oversee the issue.

Japan is the third-most-expensive country to raise a child, according to YuWa Population Research, behind China and South Korea — countries also seeing shrinking populations in worrying signs for the global economy.

Other countries are also coming to grips with ageing and shrinking populations.

China last week reported its population dropped in 2022 for the first time in 60 years.