Khan said he did not think the North Koreans are "trigger happy" and that the regime of Kim Jong Un is "not very stupid".In a phone interview with Fox News, Khan said: "Oh, no, no, no, they (the North Koreans) are not very stupid...few people blow it up and get hype, blow it against proportion."He said North Korea was a "small country" and if the US "drops a single bomb, there won't be any North Korea on the map of the world"."The North Koreans know it very well and the Americans know it very well, but for sheer propaganda and publicity both play the game," he added.North Korea's last nuclear test was conducted on February 11 with miniaturised atomic bomb of about seven kilotons mounted on a Nodong missile.Khan also acknowledged that Pakistan had collaborated in the past with North Korea on the development of nuclear weapons and missiles."Officially we had a programme with them...I went there twice...we had a missile programme," he said.It has been widely reported that Khan visited North Korea over a dozen times to secure the design of the Nodong missile, which he reportedly renamed the Ghauri.Khan was placed under house arrest in 2004 after he confessed on state-run television to running a secret nuclear proliferation ring that provided know-how and technology to countries like North Korea. In recent years, authorities have eased restrictions on Khan's movements.