THE UNITED STATES has scrambled to reinforce its Pacific missile defences, preparing to send ground-based interceptors to Guam, as North Korea said today that it had authorised plans for nuclear strikes on US targets.

US Defense Secretary Chuck Hagel said Pyongyang’s increasingly bellicose threats combined with its military capabilities represented a “real and clear danger” to the United States and to its allies South Korea and Japan.

“They have nuclear capacity now, they have missile delivery capacity now,” Hagel said yesterday. “We take those threats seriously, we have to take those threats seriously.”

The Pentagon said it would send ground-based THAAD missile-interceptor batteries to protect military bases on Guam, a US territory some 3,380 kilometres southeast of North Korea and home to 6,000 American military personnel, submarines and bombers.

They would complement two Aegis anti-missile destroyers already dispatched to the region.

Final approval for military action

Shortly after the THAAD announcement, the North Korean military said it had received final approval for military action against the United States, possibly involving nuclear weapons.

“The moment of explosion is approaching fast,” the Korean People’s Army general staff said, responding to what it called the provocative US use of nuclear-capable B-52 and B-2 stealth bombers in ongoing war games with South Korea.

Deployment of missiles

While few of the North’s threats have been matched with action, reports today said it appears to have moved a medium-range missile capable of hitting targets in Guam, South Korea and Japan to its east coast.

“We are closely monitoring whether the North moved it with a view to actual launch or just as a show of force against the US,” Yonhap news agency quoted a South Korean official as saying.

The YONHAP News Agency is reporting that Pyongyang may launch their missiles in mid-April to celebrate the 15 April birthday of Kim Il-sung, the communist nation’s founder.

Yun Duk-Min, a professor at the Korea National Diplomatic Academy in Seoul, said the latest nuclear threat was similar to one issued a month ago, but with the added weight of “approval” – presumably by North Korean leader Kim Jong-Un.

“The problem is whether Kim, who is still young and inexperienced, knows how to handle this escalation,” Yun said. “Where does it end? That’s the worrying question.”

North Korea threatened a “pre-emptive” nuclear strike against the United States in early March, and last week its supreme army command ordered strategic rocket units to combat status.

Most experts think it is not yet capable of mounting a nuclear device on a ballistic missile capable of striking US bases or territory.

The escalating crisis has triggered global concern, with China and Russia issuing repeated calls for restraint and UN Chief Ban Ki-moon warning that the situation had “gone too far” and risked spiralling out of control.

The US-Korea Institute at John Hopkins University said yesterday that a satellite photograph seen on 27 March appeared to show construction work around the reactor was already under way.

- Additional reporting by AFP