North Korea denounced South Korea and the United States on Thursday for extending their combined Vigilant Storm air exercise, calling it an "awful mistake and dangerous choice."

In a statement carried by the Korean Central News Agency, vice chairman of the Central Military Committee of North Korea's ruling Workers' Party Pak Jong-chon said that the decision by Seoul and Washington to extend the joint drills was a "very dangerous and false choice."

Pak said that the irresponsible decision is worsening the present situation caused by provocative military acts of the allied forces, pushing it into an "uncontrollable" phase.

He added that the U.S. and South Korea will discover what an "irrevocable and awful mistake" they made.

The statement came soon after South Korea and the U.S. announced plans to extend their five-day air exercise in response to the North's latest provocation, including the launch of an intercontinental ballistic missile (ICBM).