North Korea has warned the top US military commander stationed in South Korea that his forces would "meet a miserable destruction" if they go ahead with scheduled military drills.
The US plans to conduct drills alongside South Korean troops.
Pak Rim-su gave the message by phone to Gen James Thurman, commander of US Forces Korea, KCNA news agency said.
Mr Pak is chief delegate of the North Korean military mission to the inter-Korean truce village of Panmunjom
It came amid escalating tension on the divided Korean peninsula after the North's third nuclear test earlier this month, in defiance of UN resolutions, drew harsh international condemnation.
A direct message from the North's Panmunjom mission to the US commander is rare.
North and South Korea are technically still at war after their 1950-53 conflict ended in a truce, not a peace treaty.
The US-South Korean Combined Forces Command is holding an annual computer-based simulation war drill, Key Resolve, from 11-25 March, involving 10,000 South Korean and 3,500 US troops.
The command also plans to hold Foal Eagle joint military exercises involving land, sea and air manoeuvres.
About 200,000 Korean troops and 10,000 US forces are expected to be mobilized for the two month-long exercise which starts on 1 March.
The US and South Korea regularly hold military exercises which they say are purely defensive.
North Korea, which has stepped up its threats towards the United States and South Korea in recent months, sees them as rehearsals for invasion.
North Korea threatened South Korea with "final destruction" during a debate at the UN Conference on Disarmament on Tuesday.