The North Korean army said Tuesday that continuing U.S.-South Korean military exercises were tantamount to war and threatened to take action, saying the drills rendered "null and void" the armistice that ended the 1950-53 Korean War.

The statement from the North's Korean People's Army outpost at the truce village of Panmunjom comes amid renewed concerns that the communist nation is possibly planning to test a nuclear weapon, following its provocative missile launches last month.

CountryWatch: North Korea

The U.S. and South Korea on Monday launched annual military exercises, which the North had previously said would be considered a declaration of war.

The North Korean army "reserves the right to undertake a pre-emptive action for self-defense against the enemy at a crucial time it deems necessary to defend itself," the military said in a statement carried by the official Korean Central News Agency.

It wasn't immediately clear whether the North has previously made such a direct declaration calling the Korean War armistice "null and void." However, it commonly issues heated statements warning that the peninsula stands on the brink of renewed war.