North Korea blasted South Korea and the United States on Thursday for carrying out a joint military exercise, saying that it is a violation of summit agreements they reached with the North last year.

On Monday, South Korea and the US kicked off a new weeklong combined exercise named Dong Maeng that replaced their major springtime Key Resolve drills.

The military exercise, which will run through Tuesday, is seen as a scaled-down replacement for the usually two-week-long Key Resolve exercise.

"It is a violent violation of the joint declarations and statements s that North Korea reached with the US and South Korea," the Korean Central News Agency said.

"This also represents a frontal challenge to the aim and desires of all (Korean) people and the international community for peace and stability on the Korean Peninsula," it added.

South Korean President Moon Jae-in and North Korean leader Kim Jong-un met three times last year and agreed to ease cross-border tensions and foster inter-Korean cooperation.

Kim and US President Donald Trump held their first-ever summit last June that committed the two to complete denuclearization in exchange for security guarantees from Washington.

They met again last week in Hanoi, Vietnam, but their second summit failed to produce a signed statement or agreement due to differences over what North Korea should do to denuclearize and what reciprocal concessions the US should offer in return. (Yonhap)