North Korea's top envoy for normalization talks with Japan said in bilateral discussions earlier this month his country would use a "strong physical response" to economic sanctions by Tokyo, sources said Sunday.
Song Il Ho gave the warning to his Japanese counterpart, Koichi Haraguchi, during informal contacts in the course of the Feb. 4-8 meetings in Beijing, the sources said.
A Japanese delegation source described Song's remarks as an "outright threat that it would lift its freeze on launching ballistic missiles."