SEOUL: South Korea's population fell for the first time in 2020, with more people dying than were born, the government said Monday, warning that towns in poor regions faced a "crisis of extinction".

The world's 12th-largest economy has one of its longest life expectancies and one of its lowest birthrates, a combination that presents a looming demographic disaster.

As of December 31, South Korea had 51,829,023 people, down 20,838 from a year earlier, according to data released by the interior ministry.

Annual births have been falling for years and it added that they had been exceeded by deaths for the first time, 275,815 to 307,764.

"In regions with poor economic, medical and educational infrastructure, the crisis of the extinction of such towns is escalating," the ministry said.

It called for "fundamental changes" in government policies, including on welfare and education.

According to experts there are multiple causes for the phenomenon, including the expense of child-rearing and soaring property prices, coupled with a notoriously competitive society that makes well-paid jobs difficult to secure.

The double burden for working mothers of carrying out the brunt of household chores and childcare while also maintaining their careers is another key factor.

The South has spent more than 180 trillion won ($166 billion) since 2006 to boost birth rates but the population is projected to fall to 39 million in 2067, when the median age will be 62.

Reactions among South Koreans were mixed.

"The current situation will continue unless all dual-income households can afford to raise their children without any worries," one citizen posted on Twitter.

But another suggested a falling population could help reduce South Korea's carbon emissions and narrow its wealth gap.

South Korea ranks 27th globally by population and its neighbours China and Japan are also ageing rapidly.