Authorities are questioning the man who came across the border near the northeastern coast of South Korea.
A North Korean soldier has defected to South Korea, according to the Yonhap news agency.
The soldier was taken into custody in the northeastern county of Goseong early on Tuesday after crossing the border, Yonhap reported citing an unnamed military source.
It said the defector was thought to be a staff sergeant.
He was being questioned about his motives for defecting, the Reuters news agency reported, citing a South Korean defence official it did not name. The official declined to provide further details.
The defection came about two weeks after a North Korean resident crossed the border near the country’s west coast.
Crossing the heavily-fortified border between the two Koreas is extremely risky and relatively rare.
In 2017, there were a handful of defections by North Korean soldiers. One of them took advantage of thick fog to cross the demilitarized zone (DMZ).
Most North Korean civilians who leave make the journey to South Korea through China and other third countries.