South Korea and the United States have informed North Korea that they will be holding an annual joint military exercise from Monday.
The allies say the so-called Ulchi Freedom Guardian exercises will take place from August 17th to the 28th.
The drills involve tens of thousands of South Korean and American troops in a wargame that simulates an invasion by North Korea.
Officials say North Korea was informed of the allies' plans through a loudspeaker at Panmunjom, the truce village inside the DMZ.
In a statement on Saturday,... North Korea said the U.S. will be hit with the "strongest military counter-action" should the joint exercise go ahead.
The country's powerful National Defense Commission stated that North Korea is a "invincible power" with a strong nuclear deterrence.