Planned military drills between South Korean and US forces will "precipitate their self-destruction", North Korea says, the day before the exercises begin.
South Korea is a key US ally in the region and relies on US military assistance for security against the North. Troops from the two countries routinely train together, each time prompting outbursts from Pyongyang.
Monday's Vigilant Ace exercises, due to last five days, will involve more than 230 warplanes and 12,000 soldiers.
A spokesman for North Korea's Committee for the Peaceful Reunification of the Country said in the statement on Sunday that the goal of the training is to "totally destroy" North Korea, according to comments carried by North Korean state news agency KCNA.
"The US and south Korean puppet military warmongers should bear in mind that their escalating provocation and adding to crimes will only invite more terrible retaliation and precipitate their self-destruction," read the statement.
The warning comes a day after North Korea's foreign ministry warned that the US government is "begging" for a nuclear war.
Last week, North Korea launched a missile it claimed was capable of reaching the entire US mainland, raising new fears about the country's nuclear arsenal and prompting the island US state of Hawaii to sound its nuclear attack sirens for the first time since the Cold War.