VIENNA - A U.S. scientist who visited a secret North Korean nuclear site last year says Pyongyang is likely to launch a third atomic explosion test so it can develop a missile warhead.
Siegfried Hecker says North Korea's second test in 2009 was necessary because their first attempt in 2006 "didn't work well."
He said Friday that if Pyongyang wants to prove that it can develop a small, technically advanced missile warhead "they would need to have one more nuclear test."
Hecker last year was invited to North Korea, where he was shown a modern uranium enrichment plant that the North had previously denied possessing. Highly enriched uranium can be used for fissile warhead material.
Hecker is a professor in the Department of Management Science and Engineering at Stanford.
