SEJONG -- South Korea is projected to see the portion of foreign population increase by 1.2 percentage points to 4.3 percent by 2040, state demographic data showed Thursday.

The data also forecast that the portion of Korean seniors, aged 65 or over, will far outstrip that of elderly foreigners residing in the nation in 2040, suggesting that local people are aging faster than foreign residents.

According to Statistics Korea, the number of foreigners posted 1.6 million as of 2022, which accounted for 3.1 percent of the population, 51.63 million. In the population, the tally for Koreans was 50.03 million.

Though the portion of foreign population inched down from 3.3 percent in 2020 due to the pandemic, Statistics Korea predicted that the figure would rebound to 3.4 percent in 2025.

After topping 4 percent in 2035, the portion of expatriates of the population is expected to reach 4.3 percent -- 2.16 million of 50.19 million -- in 2040, said the agency.

In 2040, 35.3 percent of Koreans -- three or four in 10 people -- are projected to be aged 65 or over, while the portion of seniors among Koreans stayed at 17.8 percent in 2022.

As for foreign residents, only 12.5 percent of them are expected to make up the senior population in 18 years. Currently, only 6 percent of foreigners are aged 65 or over.

The demographic projection indicated seriousness in terms of a sharp declined in working age population over the next 18 years.

The portion of working age population -- people aged between 15 and 64 -- among Koreans is likely to plunge to 55.7 percent in 2040, from 70.5 percent in 2022.

The fast aging demographic structure has opened a public discussion that the statutory retirement age should be extended from the current 60. Calls for state pension reform had already been active.

In contrast, foreigners in the nation are expected to be robust in the working age population in 2040, when the figure is expected to record 81.6 percent of the total foreign population.

In 2022, the working age population among foreigners reached 88.7 percent.

Meanwhile, Statistics Korea forecasted that the population -- Koreans plus foreigners residing here -- will decline to 50.19 million in 2040.

Of them, the tally for Korean nationals is projected to stay at 48.03 million in 2040, compared to 50.03 million in 2022.

By Kim Yon-se (kys@heraldcorp.com)