China said its population hit 1.41 billion in 2020, eking out a tiny rise from the previous year, underlining how the world’s most populous nation is going to have to face its demographic challenges sooner than expected.

The number—up from the 1.40 billion official data showed for 2019—indicated that China’s population has only gone up by 72 million since the last census, in 2010.

In a news conference after the release, Ning Jizhe, head of the National Bureau of Statistics, said there were 12 million births last year, which would represent an 18% drop from the 14.65 million the year before, a trend that is likely to increase pressure on Beijing to ease remaining birth restrictions. It was the fourth straight year of declining births after a rise in 2016, the first year after China ended the three-decade-old one-child policy.

Mr. Ning said China’s fertility rate—the average number of babies a woman will have over her lifetime—dropped to 1.3 last year, which he acknowledged as a low level. By comparison, the U.S.—also in a fertility slump—last week reported a total fertility rate of 1.64 last year.

Meanwhile, the population of older Chinese continues to balloon.

The data showed a sharp rise in the percentage of Chinese aged 60 and above, to 18.7% of the population from 13.3% in 2010.

The portion of Chinese aged between 15 and 59 stood at 63.35% in 2020, down from 70.1% in 2010.

The pandemic’s effect on the population count was unclear. While China quickly reined in the spread of infections within its borders, demographers say coronavirus concerns probably contributed to suppressing births.

China’s demographic situation has in a short time moved to the forefront of Beijing’s economic concerns. The trend of fewer young people to replace a growing number of retirees has been clear for years but dealing with it has largely been kicked down the road as leaders have focused on mounting debt, a trade war with the U.S. and reining in a once freewheeling private sector.

Now, Beijing can no longer ignore the demographic shadow over long-term growth. Pension shortfalls in the country’s northeastern Rust Belt have forced the central government to ask state-owned enterprises as well as wealthier and younger provinces in the south to help out with the pension pool.