North Korean leader Kim Jong-un has reportedly ordered the placement of a nuclear device in a tunnel and is planning to set it off on Saturday, when the rogue state holds celebrations and parades to mark the birth of former ruler Kim il-Sung, known as the 'Day of the Sun' in North Korea.
Unconfirmed reports on the publicly-funded Voice of America, which cite American officials, claim the placing of the device underground points to an imminent test.
It comes amid escalating tensions between US President Donald Trump and the North Korean dictator.
North Korea is reportedly readying itself to launch a nuclear device
The US government and other sources are among those to say North Korea has placed the device in a tunnel for testing on Saturday, the Voice of America has claimed.
A National Security Council official said: “We have no comment at this time but we will be watching closely.”
A tweet on The Spectator Index also said commercial satellite imagery points to preparation for a nuclear test at at Punggye-ri in the remote north of the country, where previous nuclear tests have taken place.
If the test was to go ahead, it would be North Korea’s sixth ever nuclear test.
It comes on the same day as satellite images show “high levels” of activity at North Korea’s nuclear site as tensions with the US reach boiling point.
US Secretary of State Rex Tillerson has urged North Korea to destroy its nuclear armoury.
The latest images suggest recent activity around the Punggye-ri site, which has been used for previous tests with unidentified equipment now at the site.
The US has deployed forces near the Korean peninsula
Get Quotes on Home Insurance
Forbidden photographs depict the true North Korean army
Wed, April 12, 2017
While tourists are able to visit North Korea as part of a controlled tour group, they are asked by their handlers to never take photographs of soldiers. These pictures taken by photographer Eric Lafforgue show the reality of military service in the secretive state
ERIC LAFFORGUE/EXCLUSIVEPIX MEDI
1 of 25
Soldiers enjoy a ride at the funfair in Pyongyang
Joseph S Bermudez Jr and Jack Liu from North Korea think tank 38 North which monitors the hermit kingdom, said: “Over the past four weeks, there have been unusually high levels of activity at the Punggye-ri Nuclear Test Site, especially around the North Portal—the tunnel in which the four most recent nuclear tests have taken place.
Journalists visiting North Korea have have been told to prepare for a "big and important event" on Thursday as Pyongyang marks the 105th birth anniversary of its founding president Kim Il Sung on April 15, North Korea's biggest national day called "Day of the Sun”.
Tensions between North Korea and the US are at risk of boiling over
North Korea often marks important anniversaries with military parades and tests of its nuclear or missile capabilities.
The increased movement comes as tensions with the US threaten to spill over with a US Navy strike group heading towards the Korean peninsula.
Sydney-based security expert Euan Graham, of the Lowy Institute for International Policy, told 9news.au the reported preparations for a test are consistent with North Korea's strategy of "going nuclear and going early".
He said: "I'm not surprised about this reported move. It is consistent with their plan of early escalation. But it's important to realise the North Koreans have become very sophisticated in knowing what commercial satellites can view and report."
"It is possible that they are yanking our chains. There is no guarantee it will lead to a test."