On Thursday, a think tank report from inside the US Congress said that the US' controversial THAAD missile defense system that has begun to be deployed in South Korea may not be capable of actually intercepting North Korean nukes directed around the Korean Peninsula and toward Japan.
The possible locations for the killing included events at the Kumsusan Palace of the Sun, a military parade, or a public procession after Kim Jong-Un return home, according to the statement.
Pyongyang accuses US and South Korea spy agencies of attempt to assassinate country's leader with biochemical weapons.
The ministry said the spy agencies in June 2014 "ideologically corrupted and bribed" a North Korean citizen who had been working in Russian Federation to carry out the alleged assassination on Kim after returning home.
The statement, carried by North Korea's official news agency and read on state TV, didn't describe how the alleged plot was broken up or give the full name of the North Korean suspect, identifying him only by his surname, Kim, and didn't say whether anyone else was in custody. The bill targets the North Korea's shipping industry and "convict, forced, or indentured labor".
"Only the Central Intelligence Agency can produce such substance", it said, adding that South Korea had borne the funding.
North Korea, which has built a personality cult around the Kim clan, considers Kim Il Sung statues sacred.
A war of words between the West and Pyongyang has escalated in recent weeks, with North Korea threatening to carry out a sixth nuclear test.
The North Korean statement said the plan had "been put into the extremely serious phase of implementation".
North Korea warned this week that USA hostility had brought the region to the brink of nuclear war.
A statement by the North Korean Ministry of State Security said that Pyongyang would find and "mercilessly destroy" the terrorists.
It even offered to send North Korean relatives to the South to reunite with the workers, although Seoul rejected the highly unusual overture.
The report did not specify whom he was paid to assassinate.
In February, China suspended all imports of coal from North Korea as part of its effort to implement United Nations Security Council sanctions aimed at stopping the Pyongyang's nuclear weapons and ballistic-missile program.
US Secretary of State Rex Tillerson said on Wednesday that Washington was working on more sanctions against North Korea if it takes steps that merit a new response.
North Korea said it would attack the news companies if South Korea didn't apologize for orchestrating the "vicious smear campaign", although it didn't carry out the threat.