South Korea's military detained a North Korean soldier near the central section of the inter-Korean border on Tuesday night, Seoul's Joint Chiefs of Staff said on Wednesday.
Authorities were investigating the incident, JCS said in a text message to Reuters.
Yonhap News Agency reported the soldier expressed an intention to defect to South Korea, without citing a source.
North Korea should build two warships a year in next five years, Kim says
North Korea should build two warships as large as its 5,000-metric-ton Choe Hyon vessel every year in the next five years, leader Kim Jong Un said at a commissioning ceremony of a destroyer on Tuesday, according to state media KCNA.
Kim attended the ceremony held at the Nampho port in North Korea to celebrate the deployment of the new multipurpose destroyer Choe Hyon, KCNA reported.
The destroyer successfully completed military operational tests over the past 14 months, KCNA added.
The country plans to deploy another 5,000-ton destroyer named Kang Kon Soon, along with 10,000-ton strategic warships, Kim said, according to the report.
Kang Kon was repaired last year after partially capsizing during a launch ceremony.
The navy had been the weakest part of North Korea's military forces, Kim said, adding that its capabilities would now be "something incredible beyond imagination."
"Building a modernized naval base has emerged as a desperate and essential task," Kim said.
He said officials of the ruling Workers' Party's Central Committee discussed plans to build new naval bases at a meeting on Monday.
The most important change for the navy would be a shift in its status, role, and scope of operations, Kim said, without elaborating.
The navy's nuclearization is "advancing along its own course," contributing to the country's nuclear deterrence, he said.