North Korea has accused the United States of being the "main culprit behind terrorism" and claims the US tried to take out Kim Jong-un in May this year.

The secretive state, which often makes outlandish statements, claims the "main reason international terrorism is not yet annihilated" was actually because of US interference.

The statement, published on Friday by the Korean Central News Agency (KCNA), the country's main propaganda mouthpiece, claimed it foiled a US-backed attempt to depose of Kim earlier this year.

It goes on to accuse Washington of using the war on terror as a pretext for overthrowing hostile governments.

"In May this year, a group of heinous terrorists who infiltrated into our country on the orders of the Central Intelligence Agency (CIA) of the US and the South Korean puppet Intelligence Service with the purpose of carrying out a state-sponsored terrorism against our supreme headquarters using biological and chemical substance were caught and exposed," KCNA wrote.

"This palpably shows the true nature of the US as the main culprit behind terrorism."

KCNA described the United States as a "chameleon" that "changes its colours" so it can overthrow governments, particularly in the Middle East, where it used counter-terrorism and non-proliferation of weapons interchangeably to justify wars in Afghanistan, Iraq and Libya, KCNA said.

North Korea has been accusing the US and South Korea of developing a plot named as 'Plan Jupiter' a biochemical operation designed to dethrone Kim, Newsweek reported.

However these claims have not been substantiated.

The alleged May plot also accused South Korea of plotting to kill Kim, the BBC reported in May.

A North Korean known only as "Kim" was allegedly paid to carry out an attack with biochemical substances but was foiled, a statement by the North Korean ministry of state security said.

North Korea provided no other details of the fate of "Kim".

The renewed KCNA assassination claim comes as Kim acknowledged the country was faced with "ordeals" under a "stern" situation but claimed that its economy had grown this year despite ever-tighter sanctions.

He also described the North's atomic weapons as a "treasured sword" to protect it from aggression.

"The nuclear weapons of the DPRK (North Korea) are a precious fruition borne by its people's bloody struggle for defending the destiny and sovereignty of the country from the protracted nuclear threats of the US imperialists," Kim was quoted as saying.

Donald Trump has threatened to handle 'little rocket man' Kim Jong-un (Photo / Getty)

US President Donald Trump has taken a tough approach to the rogue state, calling on China to do more to reign in its ally.

In his first address to the United Nations in New York, Mr Trump also threatened to "totally destroy" North Korea.

Yesterday, he repeated his threat and said only one thing will work when it comes to stopping the secretive regime.

 Presidents and their administrations have been talking to North Korea for 25 years, agreements made and massive amounts of money paid......

— Donald J. Trump (@realDonaldTrump) October 7, 2017

...hasn't worked, agreements violated before the ink was dry, makings fools of U.S. negotiators. Sorry, but only one thing will work!

— Donald J. Trump (@realDonaldTrump) October 7, 2017

Tensions have remained high along the Korean Peninsula following a series of ballistic missile launches and North Korea's six nuclear tests this year.

Pyongyang is reportedly preparing another long-range missile test which a Russian politician claimed said could reach the US.

Anton Morozov, a member of the Russian Duma's international affairs committee and two other Russian politicians visited Pyongyang last week, RIA news agency reported.

Mr Morozov said the North are preparing for new tests of a long-range missile.

"They even gave us mathematical calculations that they believe prove that their missile can hit the west coast of the United States," he said.

North Korea often tests missiles on high-profile days and has used events including anniversaries to launch provocative missile tests.

Tomorrow, the country will celebrate another national holiday - Party Foundation Day, marking the October 10, 1945 foundation of the Central Organizing Committee of the Communist Party of North Korea.

However there was no confirmation that a launch was imminent.