North Korea appears to be preparing to test an advanced missile designed to reach the United States, a US official said, ratcheting up tensions after its second nuclear blast.

NORTH KOREA has transported its most advanced missile, believed to be capable of reaching Alaska, to a launch site on its west coast near China, news reports said.

North Korea has moved its most advanced long-range missile to a new launch site and has banned ships from the waters off its west coast until the end of July, it was reported today.

North Korea was today accused of preparing to test-fire a ballistic missile with enough range to hit the US.