Obama made the remark at a briefing on the sidelines of Group of Seven talks in Japan. (AFP Photo)
US President Barack Obama took aim at North Korea Thursday, saying it was a "big worry for all of us", after meeting with his G7 counterparts.
Obama made the remark at a briefing on the sidelines of Group of Seven talks in Japan, as regionals tensions escalate following Pyongyang's fourth nuclear test earlier this year.