North Korea condemned combined South Korea-U.S. military exercises that began Monday as a "dangerous provocative act," citing the risk of an accidental shooting sparking a physical confrontation.
The annual Freedom Shield drills are scheduled to run until March 20, although live-fire exercises remain suspended after South Korean jets mistakenly dropped bombs on a civilian town near the border last week.
That misfire wounded at least 29 people.
North Korea has traditionally called for U.S.-South Korea joint exercises to be called off, branding them as a prelude to invasion.
The South Korean military has said the joint drills aim to strengthen the readiness of the alliance for threats such as North Korea.
"This is a dangerous provocative act of leading the acute situation on the Korean peninsula, which may spark off a physical conflict between the two sides by means of an accidental single shot, to the extreme point," North Korea's foreign ministry said, according to state media KCNA.
The drills will harm U.S. security, the ministry added.
Lee Young-su, chief of South Korea's Air Force, bowed in apology Monday over the "unprecedented" accident last week where two jets mistakenly bombed the village.
"It was an accident that should never have happened and it should never happen again," Lee told reporters.
A pilot in one jet was pressed for time and did not double-check the target coordinates, while another pilot in the other jet followed and dropped bombs without noticing the incorrect coordinates, Yonhap News Agency reported, citing the interim results of the military's investigation.
The defense ministry was not immediately available for comment.
The area impacted by the accidental bombing in Pocheon, which is about 40 kilometers (25 miles) northeast of Seoul, was outside of a training area close to the border with North Korea.
Residents in the area have long complained about the disturbance and risks coming from the exercises.