The North Korean army issued a fresh threat Monday because of annual military drills South Korea and the United States began hours earlier across South Korea.
The army said in a statement Monday its troops are fully ready to "blow up" aggressors. The statement comes one day after North Korea denounced the drills as attack preparations and warned it would react by boosting its nuclear arsenal.
Pyongyang routinely escalates its threats against South Korea and the United States prior to planned military exercises, condemning them as preparation for an invasion of the North.
The U.S. and South Korean forces' joint command said Monday about 18,000 U.S. soldiers and more than 20,000 South Korean troops are taking part in the annual exercises, which it described as purely defensive.
The Key Resolve/Foal Eagle exercises run until March 18. The U.S. stations about 28,500 troops in South Korea.
The North's official Korean Central News Agency Sunday cited a senior military official as saying the drills would cause the process for the denuclearization of the Korean peninsula to come to a standstill.
The North also said it will no longer be bound by the armistice that ended the 1950-53 Korean War.
The warnings come as diplomatic efforts continue to revive stalled talks on ending North Korea's nuclear weapons program. The North quit the talks and conducted its second atomic test last year, drawing tighter UN sanctions.