North Korea has told China it intends to carry out a series of underground nuclear tests, a U.S. official told NBC on condition of anonymity on Tuesday. It also emerged that North Korea told China 20 minutes in advance on Oct. 9 that it was about to conduct a nuclear test. The cable channel CNN reported signs of preparations for a second test were detected at a new site.

CNN quoted another unnamed U.S. official as saying that activity “at a second nuclear site in North Korea is looking very similar to activity seen at another site just before the Oct. 9 nuclear test.” He reportedly said buildings and other structures “are being fabricated at this second site, possibly in an effort to hide activities from spy satellites.” CNN said there were still no sure signs of an imminent test, but there was movement at various possible test facilities in North Korea. It also said questions remain whether the U.S. will be able to spot conclusive signs even before a second test is carried out.

ABC earlier reported that U.S. spy satellites detected "suspicious vehicle movements” near the site where North Korea conducted its first underground nuclear test and the North could be preparing for another detonation. NBC also said U.S. spy satellites picked up signs of truck and people movements suspected of being preparations for another nuclear detonation. A U.S. official said that the U.S. government is “well aware” of the situation.

White House Press Secretary Tony Snow said, "It would not be unreasonable to assume the North Koreans are planning a second test," and warned such a test would only further the North’s isolation. Since the first test, “the United States and the Chinese are working more closely together than ever before," he pointed out. "And I daresay that they would become even closer as strategic partners in trying to guarantee safety in the Korean Peninsula."

(englishnews@chosun.com )