The US has reportedly called on Britain's help to tackle the problem of North Korea, requesting the UK supply RAF jets to spy on the rogue state.

At least one of Britain's three £800m Rivet Joint spy planes could go out to the region where it would be based in Japan to be joined by Korean-speaking US personnel.

The goal would be to use the planes to spy on nuclear sites and artillery batteries, the Mirror reported.

A source told the paper: "Although a conflict between North Korea and America and their allies is unthinkable, everything that can be done is being done to prepare for that if it happens.

"Western war planners are keen to minimise the death toll and that means a massive stepping-up of intelligence gathering against North Korea."

The move would require the backing of parliament but could happen within the next two weeks.

An intelligence source told the tabloid that MI6 and GCHQ are gathering information on how countries neighbouring North Korea are planning to take on the country's leader.

North Korea Responds to U.S. Sanctions

"This is all about making sure every step is taken to avoid something going wrong as efforts are made to solve this crisis through diplomacy.

"They are monitoring how Japan and China and other surrounding countries are reacting to each development."

On Thursday (10 August) US president Donald Trump issued another warning to North Korea, suggesting that his initial view that it would be greeted with "fire and fury" was not tough enough.

"I will tell you this, if North Korea does anything in terms of even thinking about attack of anybody that we love or we represent or our allies or us they can be very, very nervous," he said.

There were claims of mixed messages coming from the White House after US Secretary of State, Rex Tillerson, appeared to soften the rhetoric coming from Trump. But White House Deputy Assistant Sebastian Gorka said that the US president's sentiments should be taken seriously.

"When a group of people repeatedly says they want to kill you, sooner or later you should take them seriously. North Korea has said they wish to annihilate the United States and use nuclear weapons. Sooner or later, somebody should take them seriously," he told the BBC.