South Korea's Ministry of Unification on Sunday said almost 700 North Korean defectors' whereabouts are unknown, casting concerns over the country's settlement support system.

   The ministry said it has failed to locate 688 North Korean defectors, which accounts for 2.6 percent of the 26,000 defectors in South Korea, with 664 of them currently presumed to be overseas.

   The ministry's data also showed the number of North Korean defectors seeking to resettle in another country came to 22 this year, up from 15 last year.

   There are also 22 imprisoned defectors, while 14 others are dead or defected back to the North.

   "South Korea needs to provide customized support and social integration programs for North Korean defectors who crossed the border for freedom and abundance," Rep. Won Hye-young of the main opposition party said. (Yonhap)