US is drawing up concrete plans for a military attack on North Korea say Washington insiders

British officials are alarmed at plans the US is drawing up for a military attack on North Korea to stop its weapons programmes, it has been reported.

With Washington believing that diplomacy has reached a dead end with the rogue regime, the US has stepped up plans for options such as targeting stockpiles of weapons or destroying a launch sight, according to sources close to the administration.

Two former US officials and another figure in the administration told the Telegraph that military options were being looked at so that Pyongyang would realise Washington was serious in what would be a "bloody nose" attack.

"The Pentagon is trying to find options that would allow them to punch the North Koreans in the nose, get their attention and show that we're serious", said one former US security official.

Kori Schake, a former US director of defence strategy told the paper: "The White House very strongly believes that either North Korea will agree to give up its nuclear weapons or we will launch a preventative attack to destroy them.

"I would put the odds of them actually carrying that out at three in 10. Other policy experts say it is four in ten."

But British officials are worried that such a policy could lead to a military build-up in the region and still prefer a diplomatic process which would include pushing south-east Asian and African countries which have a lot of North Korean diplomats, to pressure the regime.

One UK source said: "The Americans said deterrence doesn't work against North Korea and negotiation doesn't work. Those who heard them left with the impression that military action is very much an option they were considering seriously."

Washington is looking to deal with Pyongyang in light of its recent tests which show that its missiles can hit Japan and South Korea.

A report in the Japanese newspaper Ashai said that the rogue regime has begun testing the loading of the highly infectious killer bacteria anthrax on to intercontinental ballistic missiles.

The US is uncertain of what Kim Jong-Il would do if provoked and US Secretary of State Rex Tillerson and defence secretary Jim Mattis, are said to be less keen on military action. There has been no comment from the Pentagon, the US State Department or the White House.