South Korea's main opposition parties strongly objected Monday to any attempt by the government to sign a bilateral agreement with Japan on sharing military intelligence, threatening to "dismiss or impeach" the defense minister if the deal goes through.

South Korean Defense Ministry spokesman Moon Sang-gyun said at a press briefing that "priority has been put on the importance of national security" in seeking the agreement with Japan to better cope with North Korea's nuclear saber-rattling.

South Korean media have reported that plans to sign the deal were set to go ahead as officials met Monday in Tokyo for a third round of talks.