The United States has decided to delay a long-planned missile test scheduled for next week out of California "to avoid any misperception or miscalculation", given tensions with North Korea, a senior US defence official has said.

The unusual precaution by the US follows a barrage of hostile rhetoric from North Korea - including the threat of open war - that has created jitters in South Korea's financial markets.

The US decision will delay the test of the Minuteman III intercontinental missile, which had been scheduled for next week out of Vandenberg Air Force Base in California.

"This is the logical, prudent and responsible course of action to take," the official said on Saturday, speaking on condition of anonymity.

"This is the logical, prudent and responsible course of action to take."

- US official, speaking on condition of anonymity.

It also came after reports in the South that Pyongyang, under its 30-year-old leader, Kim Jung-un, had moved two medium-range missiles to a location on its east coast.

The White House said on Friday it would "not be surprised" if the North staged another missile test. At the same time, officials have said there are no signs Pyongyang is gearing up for war, such as large-scale troop movements.

The US official said the test had been unconnected to "anything related to North Korea" and added that another test launch could be expected next month.

The US remained fully prepared to respond to any North Korean threat, the official said.

Rising tensions

Analysts are looking anxiously ahead to April 15, the birthday of King Il-sung, North Korea's founder and the grandfather of its current leader.

The anniversary is a time of mass celebrations, nationalist fervour and occasional demonstrations of military prowess.

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North Korean authorities have told diplomatic missions they could not guarantee their safety from next Wednesday - after declaring that conflict was inevitable amid joint US-South Korean military exercises due to last until the end of the month.

Still, staff at embassies in North Korea appeared to be remaining in place on Saturday despite the appeal.

Most countries saw the appeal to the missions as little more than strident rhetoric after weeks of threats by North Korea to launch a nuclear strike on the US and declarations of war against the South.

Washington has been running military drills and war games with South Korea in past weeks, including flying two B-2 stealth bombers over the Korean peninsula in March.

The Pentagon also announced new or expanded missile defence systems in Alaska and Guam.

North Korea's inflammatory threats following the annual US-South Korea war games are seen by some analysts as an attempt to mask their fear that the exercises could turn into an all-out attack - and 'seems to work on the principle that the more you shout, the safer you will be'.

The North's rhetoric intensified after UN sanctions intensified since April 2012 in the wake of rocket and nuclear tests.

Source: Al Jazeera And Agencies