North Korea's "reckless" military provocations, as a new dispute erupted between the two countries over four defectors from the communist state.President Lee Myung-Bak stressed the need for separate branches of the military to work together to counter the threat from the North's special warfare forces, which Seoul says number 200,000.
"Through reckless military provocations, they (the North) are continuing to threaten peace," he told a multi-service officer commissioning ceremony at Gyeryongdae, 160 km south of Seoul.
The defector dispute is the latest episode in a year of high tensions and comes as US and South Korean troops stage major military exercises that the North has branded a rehearsal for invasion.
The South tried Friday to repatriate 27 North Koreans whose boat drifted across the border on February 5. But it says two men and two women who were on the boat chose to stay in the South -- a claim rejected by Pyongyang.
The North as of late afternoon had refused to send anyone to the frontier village of Panmunjom to accept the 27, apparently because it also wants the other four also to be returned.
A Seoul unification ministry front man said there was no word from the North on the transfer as of 6pm.
The communist state late Thursday accused the South of "despicable unethical acts" and said the group on the boat had been held hostage in a bid to fuel cross-border confrontation.
But Seoul said the four had not been forced to stay.