North Korea on Friday accused the CIA of plotting with South Korea to assassinate the isolated country's leader Kim Jong-Un, amid soaring tensions in the flashpoint region.
The CIA and Seoul's Intelligence Services have "hatched a vicious plot" involving unspecified "biochemical substances" to assassinate the hermit state's young leader during public ceremonial events in Pyongyang, the Ministry said in a statement carried by state media.
For the CIA "assassination by use of biochemical substances including radioactive substance and nano poisonous substance is the best method that does not require access to the target, their lethal results will appear after six or twelve months," the North Korean Ministry said in a statement carried by state media on Friday.
The North Korean Ministry vowed to launch an "anti-terrorist" attack against the United States and South Korea following its claims about the assassination plot.
"We will ferret out and mercilessly destroy to the last one the terrorists of the US CIA" and South Korea's National Intelligence Service "targeting the dignity of the DPRK supreme leadership," North Korea's Ministry of State Security said.
"A Korean-style anti-terrorist attack will be commenced from this moment to sweep away the intelligence and plot-breeding organisations of the US imperialists and the puppet clique."
The accusation comes amid claims that Kim could be planning an attack on South Korea after he inspected an artillery unit used to bombard the country in the last deadly clash between the two countries.
Pyongyang has issued increasingly belligerent rhetoric in a tense stand off with the Trump administration over its rogue weapons program.
The war of words between the West and the reclusive regime has spiked in recent weeks, and Pyongyang has threatened to carry out a sixth nuclear test that would further inflame tensions.
The CIA and Seoul's Intelligence Services (IS) have "deologically corrupted and bribed a DPRK citizen surnamed Kim who worked as a lumberjack in the Khabarovsk Territory of Russia to carry out the attack on Jong-Un, the statement said.
"They hatched a plot of letting human scum Kim commit bomb terrorism targeting the supreme leadership during events at the Kumsusan Palace of the Sun and at military parade and public procession after his return home," KCNA said.
"They told him that assassination by use of biochemical substances including radioactive substance and nano poisonous substance is the best method that does not require access to the target, their lethal results will appear after six or twelve months.
"Then they handed him over $20,000 on two occasions and a satellite transmitter-receiver and let him get versed in it."
The statement said that the plot to kill Kim was tantamount to "the declaration of a war".
"We will ferret out and mercilessly destroy to the last one the terrorists of the US CIA and the puppet IS of South Korea," the statement said.
It added: "The heinous crime, which was recently uncovered and smashed in the DPRK, is a kind of terrorism against not only the DPRK but the justice and conscience of humankind and an act of mangling the future of humankind."
The statement did not give any information on how the plot was foiled or what happened to the alleged spy.
The US Embassy in Seoul and South Korea's National Intelligence Service were not immediately available for comment. The U.S. military has said CIA director Mike Pompeo visited South Korea this week and met the NIS chief for discussions.
North Korea conducted an annual military parade, featuring a display of missiles and overseen by top leader Kim Jong Un and his right-hand men on April 15 and then a large, live-fire artillery drill 10 days later.
KCNA, which often carries shrill, bellicose threats against the United States, gave lengthy details about the alleged plot but said it could never be accomplished.
"Criminals going hell-bent to realise such a pipe dream cannot survive on this land even a moment," it said.
North Korea maintains extensive surveillance operations over its own population, and open dissent against the regime is considered extremely difficult.
Meanwhile, Kim visited the "Hero Defence Detachment" on Mu Islet on Friday, telling troops to "keep highly alert to break the backbone of the enemy", the state-backed Korean Central News Agency reported.
Kim also praised the unit's 2010 shelling of South Korea's Yeonpyeong Island, which killed four including two civilians, as "the most delightful battle".
The dictator branded the shelling "brilliant military service" saying it was an example to "hand down through the generations", a state media release said.
His visit was to assess the 'combat readiness' of the unit as fears of a fresh and bloody conflict in the region grow.
State media said Kim inspected new fire plans to be used in "the future battle", and "confirmed that all positions are fully ready for combat and to go into action."
North Korea's shelling of Yeonpyeong in November 2010 came as the result of what it called a "provocative shelling by the South Korean puppet warmongers."
South Korea had been conducting a drill on Yeonpyeong in which it fired live shells into the ocean. North Korea accused Seoul of shooting into its territorial waters, a claim the South disputes, and returned fire.
In total 170 rockets and shells were fired at the island, which was then home to around 2,000 people, destroying multiple buildings and military installations.
Two members of the South Korean military were killed, along with two 60-year-old constructions workers.
Seoul said it retaliated against the North, hitting several gun positions on Mu Islet. North Korea made no mention of anyone being killed.
Meanwhile, the Republican-led US House of Representatives overwhelmingly voted to impose new sanctions on North Korea this week, targeting its shipping industry and use of slave labour.
Members approved the measure 419-1 as tensions continued to mount over Pyongyang's advancing nuclear and ballistic missile programs.
Admiral Harry Harris Jr, the top American military officer in the Pacific, has warned it is a question of when, not if, North Korea successfully builds a nuclear-tipped missile capable of striking the US.
The Senate must take up the measure next. The bipartisan legislation is aimed at thwarting North Korea's ambitions by cutting off access to the cash the regime needs to follow through with its plans.
The measure is sponsored by Rep Ed Royce of California, the Republican chairman of the House Foreign Affairs Committee, and Rep Eliot Engel of New York, the committee's senior Democrat.
The bill bars ships owned by North Korea or by countries that refuse to comply with UN resolutions against it from operating in American waters or docking at US ports.
Goods produced by North Korea's forced labour would be prohibited from entering the United States, according to the legislation.
Anyone who uses slave labour that North Korea exports to other countries would be subject to sanctions under the International Emergency Economic Powers Act, the bill states.
At times when the nation is facing unusual or extraordinary threats, the President has wide authority under the law, including the power to block or prohibit transactions involving property located in the US.