Pictures show how a PAC-3 Patriot missile unit has been moved in to a compound at the Defence Ministry in the capital after officials said they could shoot down North Korean rockets if they pass overhead.
Sales of bomb shelters in Japan are said to have increased as tensions continue to rise in the region while officials in Seoul have vowed to bolster their defences. But South Korean citizens - long accustomed to its neighbour's fearsome rhetoric - are staying remarkably calm as the crisis unfolds, it has been reported.
Officials in Hawaii, meanwhile, say they are working on how to warn its 1.4million residents in the event of an attack.
It comes after North Korea warned it will complete a plan to unleash an 'enveloping fire' around Guam by mid-August. This will involved firing four Hwasong-12 missiles over Japan and into waters near the tiny US island, officials claimed.