This file photo, provided by Yonhap News TV on Oct. 24, 2023, shows a North Korean wooden ship used by North Korean residents to defect to South Korea being towed by a South Korean vessel in the East Sea. Yonhap

A North Korean man has crossed the de facto western maritime border into South Korea aboard a wooden boat, a South Korean military official said Friday, in the third defection in two months.

South Korea's military monitored his activities and later assisted him in arriving in South Korea when his small boat crossed the Northern Limit Line near South Korea's border island of Baengnyeong in the Yellow Sea in the early hours of Sept. 17.

"The operation took place normally from an early stage," the official said, without providing any further details on the defector's identity and the operation.

The announcement of the latest defection came just two days after North Korea's military said that it would "permanently shut off and block the southern border" in what Adm. Kim Myung-soo, chairman of South Korea's Joint Chiefs of Staff, said is an attempt to prevent people from defecting from North Korea.

After North Korean leader Kim Jong-un defined inter-Korean relations as those between "two states hostile to each other" late last year, the North has taken steps to close inter-Korean land routes, reinforcing border fortifications and removing rails that once connected the two Koreas.

The inflow of North Korean defectors has continued amid chronic food shortages and harsh political oppression in the North. In the first half of the year, the number of North Korean defectors arriving in the South reached 105, slightly up from 99 the previous year.

In August, a North Korean soldier crossed the heavily fortified inter-Korean land border while another North Korean resident defected by crossing the neutral zone of the Han River estuary.

Tensions have simmered over the North's continued launches of balloons carrying trash into South Korea, which has prompted Seoul to blast anti-Pyongyang propaganda broadcasts through its military loudspeakers on the border.

North Korea has launched thousands of trash balloons since late May in what it has described as a "tit-for-tat" move against anti-Pyongyang leaflets sent across the border by activists and North Korean defectors in South Korea. (Yonhap)