SEOUL, South Korea (CBSNewYork)North Korean state media accused the United States and South Korea of attempting to assassinate leader Kim Jong-un with biochemical weapons.

The purported plot started in June 2014 and involved a North Korean working in Russia, according to North Korea’s Ministry of State Security.

READ MORE: Police: Man Stabbed In Head With Machete After Argument At Walmart In Kearny, N.J.

The ministry claimed that the “ideologically corrupted and bribed” North Korean was given money and satellite communication equipment to help carry out the plot, which allegedly involved a radioactive or poisonous substance.

The plot appears to echo the assassination of Kim Jong-un’s half-brother at an airport in Malaysia. Two women were accused of smearing the chemical agent VX on his face, which resulted in his death. The assassination was widely blamed on North Korea, which denied involvement.

READ MORE: New York Weather: CBS2’s 9/25 Saturday Morning Forecast

North Korea’s claim of the assassination plot comes as tension between the isolated nation and the U.S. and others continued to mount over North Korea’s missile tests and pursuit of nuclear weapons. On Wednesday, North Korea detained a U.S. citizen. Three Americans are now being held there.

President Donald Trump said he “would not be happy” if North Korea tested another nuclear weapon.

MORE NEWS: Some Real Estate Agents Report Surge Of New Yorkers Moving From Manhattan To The Bronx

A U.S. aircraft carrier group has moved into the region.