ⓒYONHAP News

U.S. Deputy Secretary of State Stephen Biegun and South Korea's top nuclear envoy Lee Do-hoon appeared content with their discussions of what they called "creative ideas."

After their meeting in Washington on Monday, the two noted that the ball is now in North Korea's court.

"The United States and the Republic of Korea remain fully committed to diplomacy as a way to reach an enduring peace on the Korean Peninsula, to achieve denuclearization, to bring about a brighter future for all Korean people, and to bring about normalcy in the United States' relationship with the DPRK. I very much appreciate the encouragement and the creative ideas that we discussed today. But we cannot do it by ourselves. The U.S. and ROK cannot do this by ourselves. we need the DPRK engaged, and we remain open to the discussion with them when they're prepared. Ambassador Lee."

"Well, thank you Mr. Deputy Secretary. Thank you very much for having me here. As I told you earlier that it has been two years since we started working together. I think I have to say that you are the best interlocutor in my career."

Lee told Korean reporters that the meeting was the best among recent ones.

The talks came less than a week after South Korean President Moon Jae-in called for global support in declaring an official end to the Korean War, which ended in an armistice in 1953 instead of a peace treaty. But the reconciliatory effort was dampened by the North's killing of a South Korean fisheries official.

"Of course, we discussed the tragic killing of a fisheries official in the West Sea - something that was deeply disturbing to the Korean people and certainly to the United States of America. But we also talked about constructive ways to continue to advance our diplomacy on the Korean Peninsula together."

In a bid to revive the dying momentum for nuclear talks, Moon suggested in his speech at the 75th UN General Assembly that a war-ending declaration will serve as a gateway to denuclearization and permanent peace on the Korean Peninsula.

Shortly after the inter-Korean summit in Pyongyang two years ago, cross-border relations started to collapse particularly following the breakdown of the Washington-Pyongyang summit in Hanoi last year. Despite the North's explosive demolition of the inter-Korean liaison office in the border area, Seoul has so far been mediating between Washington and Pyongyang while searching for small-scale inter-Korean projects that may not be subject to U.S. nuclear sanctions.