The top nuclear envoys of South Korea and the United States condemned Saturday North Korea's latest missile test and vowed to boost coordination during phone consultations, Seoul's foreign ministry said.

Earlier in the day, the North test-fired a ballistic missile toward the East Sea from around the Sunan area in Pyongyang, less than a week after a ballistic missile launch, according to the South's military.

Noh Kyu-duk, special representative for Korean Peninsula peace and security affairs, and his US counterpart Sung Kim denounced the North for its successive missile launches in violation of the United Nations Security Council resolutions, the ministry said.

They also agreed to maintain a watertight defense posture and boost close consultations to prevent the North from aggravating the situation, it added.

Saturday's firing is the ninth show of force by the communist country this year, and came just four just four days ahead of South Korea's presidential election. (Yonhap)