Washington. The United States said it would soon send a missile defence system to Guam to defend it from North Korea, as the US military adjusts to what Defense Secretary Chuck Hagel called a "real and clear danger” from Pyongyang.Hours later, South Korea’s Yonhap news agency said North Korea had moved what appeared to be a mid-range Musudan missile to its east coast. It was not clear if the North planned to fire the rocket or was just putting it on display as a show of force, one South Korean government source was quoted as saying.North Korea also barred entry to a joint industrial complex it shares with the South for a second day on Thursday and said it would shut the zone if Seoul continued to insult it.Events on the Korean peninsula have begun to unnerve global financial markets long used to the rhetoric North Korea routinely hurls at Seoul and Washington."The assumption remains that this is more bluster ...,” said Rob Ryan, a strategist with RBS in Singapore. "But from here, we’ve reached a level of tensions that say things can’t get too much worse without an actual exchange of fire.”The broadest index of Asia-Pacific shares outside Japan was down 0.6 percent, dragged down by a 2 percent slump in South Korean shares, while the South Korean won slid 0.7 percent against the US dollar.US stocks sank on Wednesday after Hagel’s comments and the Guam deployment news.North Korea also repeated its threat to launch a nuclear attack on the United States. Pyongyang said it had ratified a potential strike because of US military deployments around the Korean peninsula that it claimed were a prelude to a possible nuclear attack on the North.Washington had been informed of the potential attack by North Korea, a spokesman for its army said in a statement carried by the English-language service of state news agency KCNA. It was unclear how such a warning was given since North Korea does not have diplomatic ties with Washington.The report from KCNA appeared to re-state many of the month-long fusillade of threats emanating from Pyongyang.North Korea has previously threatened a nuclear strike on the United States and missile attacks on its Pacific bases, including in Guam, a US territory in the Pacific.Those threats followed new UN sanctions imposed on the North after it carried out its third nuclear test in February."Some of the actions they’ve taken over the last few weeks present a real and clear danger,” Hagel told an audience at the National Defence University in Washington.Despite the rhetoric, Pyongyang has not taken any military action and has shown no sign of preparing its 1.2 million-strong armed forces for war, the White House said on Monday.That indicates its threats are partly intended for domestic consumption to bolster young leader Kim Jong-un ahead of celebrations marking the anniversary of the April 15 birthday of Kim Il-sung, the state’s founder and the younger Kim’s grandfather.