 North Korea threatens U.S. with nuclear retaliation. North Korea has threatened a nuclear response if the U.S. deploys aircraft carriers, bombers and missile submarines in South Korea according to a statement shared by state media channel KCNA. Pyongyang claims that despite repeated warnings, Washington and Seoul held a meeting of the nuclear consultative group on July 18 to allegedly discuss using nuclear weapons against North Korea. In particular, the hostile forces posed the most undisguised and direct nuclear threat to North Korea by bringing an Ohio-class strategic nuclear submarine to the Busan port operation base, which means strategic nuclear weapons have been deployed on the Korean Peninsula. For the first time after 40 odd years, North Korean Defense Minister Kang Sunnam said in the statement. He claimed that the move indicates that the U.S. scenario for a nuclear attack on North Korea had entered the most critical stage of visualisation and systemisation. Kang accused Washington and Seoul of going beyond the red line in their military hysteria and argued that the deployment of nuclear submarines and other strategic assets falls under the conditions for the use of nuclear weapons specified in North Korean military doctrine. The North Korea's doctrine on the use of nuclear weapons allows the execution of necessary action procedures in case a nuclear attack is launched against it or it is judged that the use of nuclear weapons against it is imminent. Kang said. He also called on the U.S. military to realise that its nuclear assets had entered extremely dangerous waters.