South Korea’s defense ministry said Thursday that North Korea appeared to be preparing to launch a long-range missile, state news agency Yonhap reported. Officials and Japan’s national broadcaster NHK reported activity at a site in the west of the Hermit Kingdom, where its Sohae launching station is located. Ministry spokesman Moon Sang-gyun also said Seoul was preparing its air defense in order to intercept any missile or debris falling in its territory. Pyongyang said this week it was planning to launch a satellite this month, sparking international backlash from critics who said it was a cover-up to test missile technology. Tensions have escalated with the North Korea since Pyongyang carried out its fourth nuclear test on Jan. 6.