WANDO, South Korea — After Park Pil-soo's second child was born nine years ago, he followed national family planning entreaties to limit families to two children by undergoing a free, government-sponsored vasectomy.

Then, in April, Park took advantage of a new policy and had the vasectomy reversed, also at the state's expense. He and his wife, Yang Eun-hwa, 36, are now trying to have a third child.

After decades of promoting smaller families, South Korea — like several other Asian countries facing plummeting birthrates — is desperately seeking ways to get people to have more babies.

In South Korea, the decline has been so precipitous that it caught the government off guard. Policies devised to discourage more than two children, like vasectomies and tubal ligations, were covered under the national health plan until last year. This year, the plan began covering reverse procedures for those two operations, as well as care for a couple's third or fourth child.

"I'd been thinking about getting the operation for a while, but was concerned about the cost," said Park, 37, who runs the Samsung Electronics store in this seaside town on the southern shore of the Korean peninsula.

In South Korea, as in Japan, Taiwan, Singapore and Hong Kong, quick economic growth and social changes have produced disturbingly low birthrates that are transforming their societies and threatening their economic strength. In this ethnically homogenous nation, as in Japan, there is no support for the kind of immigration that has increased birthrates in some Western nations, including the United States.

"In the next two or three years, we won't be able to increase the birthrate," said Park Ha-jeong, a director-general in the Health Ministry. "But we have to stop the decline, or it will be too late."

Young couples in Seoul and other cities are choosing to have few babies, but the low birthrate has hit rural places like Wando County hardest. Within less than a decade, it has transformed South Korea's rural landscape, shuttering schools, shrinking class sizes, setting off village-wide celebrations for the rare birth of a baby.

Growing up here, Park Pil-soo has watched family sizes shrink to fewer than two children from as many as eight, and Wando's population decreases year by year. People have grown richer here. At his Samsung store, residents began buying air-conditioners four years ago, and they expect television sets in each room and a refrigerator just for kimchi.

"People now want a higher living standard instead of children," he said, as he and his wife attended to customers on a recent Saturday.