POSTED: Thursday, February 7, 2013 - 9:00am
UPDATED: Thursday, February 7, 2013 - 9:04am
NBC News — South Korea's Defense Ministry thursday said North Korea could possibly detonate a "boosted fission weapon." During a news conference in Seoul, a defense ministry spokesman said "it is possible if they add tritium or heavy hydrogen to plutonium, which induces bigger explosions with much energy from the bomb."
North Korea has threatened to attack South Korea if Seoul joined a new round of tougher U.N. sanctions. Washington and Seoul are getting tougher with Pyongyang after North Korea's last rocket launch in December. The north has declared a boycott of all dialogue aimed at ending its nuclear program and vowed to conduct more rocket and nuclear tests.