MAPPED: Are Europe and US targets? These are the countries North Korea can hit with a NUKE

North Korea could one day possess missiles that could strike the US

Defence officials have warned that the latest test poses a "threat to the peace and security of the entire north east Asia region".

But it is not just North Korea's neighbours that fear the development of nuclear weapons by the posturing despot Kim Jong-Un.

The US government and military chiefs are in agreement that the rogue communist state has the potential to strike targets in America, including the states of Alaska and Hawaii.

A map showing the potential targets

Nuclear experts believe North Korea is developing the KN-08 rocket that has a range of 5,600miles - far enough to hit locations as distant as Germany and California.

The Taepodong rocket is another of its feared missile development programmes.

The rocket could one day be capable of striking targets as far away as Australia and Alaska.

But efforts to perfect multi-stage ballistic missiles capable of being fired across continents have been failing for more than a decade.

While they theoretically have the ability to hit California and other locations on America's west coast, the communist regime has never actually demonstrated the capability to launch or test those missile systems, said Dr Robert Winstanley-Chesters, a North Korea expert.

Speaking to Express.co.uk, he said to date Pyongyang's only tried and tested missile system was the Nodong, which has a range of 1,000km.

However North Korea has only ever tested the Nodong at a range of 600km - still far enough to hit South Korea, China and a small area of Russia but wihtout the sufficient range to strike Japan.

That places China, South Korea, Japan, Mongolia and parts of Russia firmly in the nuclear crosshairs.

Sanctions placed on North Korea by the rest of the world have also made it more difficult to access the kind of finely engineered machinery necessary to make the technological jump.

One factor holding back North Korea's missile programme is the ability to scale down a nuclear weapon to fit on an intercontinental missile.

However, Tatsujiro Suzuki, professor at the Research Centre for Nuclear Weapons Abolition at Nagasaki University in Japan, said it was possible to fire the latest test device over long distances.

He said: "That the bomb can become compact is the characteristic, and so this means North Korea has the US in mind in making this H-bomb announcement."

Even if North Korea has fully functional hydrogen bombs and a carrier system capable of hitting the US, many believe it is unlikely to launch them.

The survival of the regime is top of Kim Jong-un's agenda and, even with a handful of nuclear weapons, he knows the US has thousands of similar warheads.

Dr Winstanley-Chesters added: "I think that North Korea knows if it was to launch a nuclear attack they would know it's game over."

North Korea's claims to have tested the device have also been rejected by experts who believe the pariah state is merely "bluffing".

North Korean leader Kim Jong-un

A ballistic missile is paraded in Pyongyang, North Korea

People watch a news report on North Korea's first hydrogen bomb test

Dr Alan Mendoza, executive director at Henry Jackson Society, told Express.co.uk: "Most experts believe North Korea is bluffing about the type of test it claims to have conducted.

"But even if so, this episode once again shows why allowing rogue regimes to develop nuclear weapons is highly dangerous.

"Having failed to stop North Korea from taking its first nuclear step some years ago, we now have to rely on the good faith of a 32 year old despot, Kim Jong-un, that he will never use them or develop further destructive capabilities.

"As this test shows, we can't guarantee that, which is why pandering to other nuclear aspirants like Iran is always a mistake."