(From Top) South Korean's special representative for Korean Peninsula peace and security affairs Lee Do-hoon, the Japanese foreign ministry's director general of Asia and Oceania affairs Kenji Kanasugi, and the United States top nuclear envoy Stephen Biegun. Yonhap, AFP-Yonhap

The top nuclear envoys of South Korea and the United States met in Washington Wednesday and agreed to continue close coordination on North Korea, Seoul's foreign ministry said.

Lee Do-hoon, South Korean's special representative for Korean Peninsula peace and security affairs, held talks with his American counterpart, Stephen Biegun, in the wake of last week's second summit between U.S. President Donald Trump and North Korean leader Kim Jong-un.

The leaders met in Hanoi, Vietnam, on Feb. 27 and 28 but failed to reach an agreement on dismantling the North's nuclear weapons program.

South Korea is keen to ensure momentum in U.S.-North Korea talks to achieve its ultimate goal of lasting peace on the peninsula.

"The U.S. side provided a more detailed explanation of the outcome of the second North Korea-U.S. summit, South Korea and the U.S. compared notes on the summit and held talks on the next steps," the ministry said in a press release.