(FILES) This file photo taken on August 25, 2016 shows a man at a railway station in Seoul watching a television screen reporting news of North Korea's latest submarine-launched ballistic missile test. Recent satellite photos suggest North Korea could be preparing for fresh submarine-based ballistic missile tests, an expert on its military said on August 11, 2017. Joseph Bermudez, a specialist in North Korean defense and intelligence affairs, posted photographs on the authoritative 38 North blog of the US-Korea Institute at Johns Hopkins University which he said could show preparations for a test of a submarine-launched ballistic missile (SLBM). / AFP PHOTO / JUNG YEON-JE