North Korea's ambassador to the UK has said people who defect are "scum" and "animals".
In a rare interview, Hyun Hak-bong indicated his country can fire a nuclear weapon "at any time".
He was speaking as the US and South Korea carry out annual military exercises, described by the ambassador as an act of aggression.
"They want (North Korea) to get used to (the military exercises) and get relaxed," he claimed. "When we are relaxed, they want to make a surprise and pre-emptive strike. This is their true colours."