North Korea ready to carry out nuclear test at any moment, Seoul says May 24, 2012 -- Updated 0434 GMT (1234 HKT) South Korea says the images suggest the North is ready to conduct the test at any time North Korea is "awaiting a political decision" on the test, Seoul says Seoul, South Korea (CNN) -- North Korea appears to be ready to carry out a nuclear test whenever leaders of the reclusive state give the green light, a spokesman for the South Korean Defense Ministry said Thursday. The comment follows an analysis of recent commercial satellite images by the defense publication IHS Janes, which suggested activity was being ramped up at North Korea's nuclear test site. Mining carts and excavation equipment at the tunneling area of the North's Punggye-ri site can be seen in satellite images taken by Digital Globe and GeoEye in the past month. "Based on the sand piles from the commercial satellites, we are assuming that they have put necessary devices for a nuclear test inside the shaft," Kim Min-seok, spokesperson for South Korea's defense ministry said in a regular briefing Thursday. This means they can conduct a nuclear test any time. He said North Korea was "awaiting a political decision" on whether or not to go ahead with the test, the prospect of which has strained relations between Pyongyang and other countries.