North Korea: US to move missiles to Guam

The US has announced it is moving an advanced missile system to the Pacific island of Guam as North Korea steps up its warlike rhetoric.

The latest statement from Pyongyang "formally informs" the Pentagon it has "ratified" a possible nuclear strike.

Pyongyang has threatened to target the US and South Korea in recent weeks.

The US Department of Defense said on Wednesday it would deploy the ballistic Terminal High Altitude Area Defense System (Thaad) in the upcoming weeks.

The Thaad system includes a truck-mounted launcher, interceptor missiles, and AN/TPY-2 tracking radar, together with an integrated fire control system.

North Korea's warlike statements follow fresh UN sanctions and joint military drills by the US and South Korea.

The Pentagon said the missile system would be moved to Guam, a US territory with a significant US military presence, as a precautionary move to strengthen our  defence posture against the North Korean  ballistic missile threat.

"The United States remains vigilant in the face of North Korean provocations and stands ready to defend US territory, our allies, and our national interests," the Pentagon added.

The US had planned to send a Thaad system to Guam, but not under these conditions, analysts say.

Later on Wednesday, a statement carried by the official North Korean news agency said: "We formally inform the White House and Pentagon that the ever-escalating US hostile policy towards the DPRK [North Korea] and its reckless nuclear threat will be smashed by the strong will of all the united service personnel and people and cutting-edge smaller, lighter and diversified nuclear strike means of the DPRK and that the merciless operation of its revolutionary armed forces in this regard has been finally examined and ratified."

In recent weeks, North Korea has stated military bases in the US territory of Guam and the US state of Hawaii as possible targets.

"As they have ratcheted up her bellicose, dangerous rhetoric, and some of the actions they've taken over the last few weeks present a real and clear danger," said US Defence Secretary Chuck Hagel, in his first major speech on Wednesday since taking up his post.

He added that Pyongyang had also threatened the interests of South Korea and Japan.

The North has apparently been angered by UN sanctions imposed after a recent nuclear test. Pyongyang has escalated its warlike rhetoric amid the current round of US-South Korea military drills.

The US has recently made a series of high-profile flights of stealth fighters and nuclear-capable B-52 bombers over South Korea.

Officials have also confirmed that the USS John McCain, an Aegis-class destroyer capable of intercepting missiles, has been positioned off the Korean peninsula.

A second destroyer, the USS Decatur, has been sent to the region.

On Tuesday, US Secretary of State John Kerry called recent North Korean actions "dangerous" and "reckless".