The country’s Foreign Minister Taro Kono said: “[North Korea] is doing everything possible to prepare for the next nuclear test: it is currently extracting earth from an underground tunnel where the previous test was carried out.”

The minister said previously the secretive state “does not reveal its intentions to the outside world in terms of denuclearisation”.

The Yongbyon experimental light water reactor in North Korea, suggesting trial operations are under way. Picture: Associated PressSource:Supplied

At the end of last year the tyrant declared his country a fully fledged nuclear power after launching a new missile he claimed was capable of hitting anywhere on the planet.

Nuclear devices are often tested underground to prevent radioactive material released in the explosion reaching the surface and contaminating the environment — this method also ensures a degree of secrecy.

The release of radiation from an underground nuclear explosion — an effect known as “venting” — would give away clues to the technical composition and size of a country’s device.

A test site is carefully geologically surveyed to ensure suitability — usually in a place well away from population centres.

The nuclear device is placed into a drilled hole or tunnel usually between 200-800m below the surface, and several metres wide.

North Korean leader Kim Jong-un delivering his speech during a military parade in Pyongyang in February. Picture: AFPSource:AFP

Up to 200 people were thought to have died at the Punggye-ri nuclear test site in the northeast of the country.

The accident was believed to have been caused by Kim Jong-un’s sixth nuclear test which weakened the mountain, according to the report.

Former British Defence Secretary Sir Michael Fallon previously warned that Britain is at risk from North Korea’s long-range nuclear missile program as some cities are closer than American targets.

Revised estimates suggest the total number of missiles the rogue state has is believed to be between 13 and 21.

And the regime is estimated to have at least four nuclear warheads.

Satellite images of Jong-un’s main missile test site in August revealed North Korea’s weapons were more powerful than initially thought.

Careful analysis of North Korean tests sites, using images from Planet, reveal the regime has been gradually building up the size of its missiles.

This article originally appeared on The Sun and has been republished with permission.

Source: http://www.news.com.au/world/asia/north-korea-is-preparing-for-nuclear-test-by-digging-tunnel/news-story/69fe873a70328b72addac06b9924c3d2