(CNN) - The North Korean army announced today that the armistice agreement that ended the Korean War is now invalid.
The ceasefire agreement, signed in 1953, ended the three-year war between North and South Korea in a truce. Since the two sides remain technically at war, it remains to be seen whether the invalidation means that either side can resume hostilities.
Since last week, North Korea had been threatening to scrap the armistice after the U-N Security Council passed tougher sanctions against it. The sanctions were in response to North Korea's February 12th nuclear test. The North has declared the ceasefire null several times in the past.
The declaration follows the start of joint military exercises this morning between the U-S and South Korea. North Korea has called the drills "an open declaration of war."