The new U.S. point man on North Korea says Washington and Seoul will need to do all they can to make the most of the moment of opportunity created by the summits among leaders of the U.S. and the two Koreas to denuclearize the Korean Peninsula.

At a meeting with his South Korean counterpart Lee Do-hoon in Seoul Tuesday, U.S. Special Representative for North Korea Stephen Biegun said they have some hard work to do, but they also have a tremendous opportunity.

Citing the Korean proverb that "the beginning is half done," Biegun said efforts for peace have begun and it's time to finish the job.

Lee, on his part, said Seoul, Washington and Pyongyang are facing both challenges and opportunities in terms of making headway in denuclearizing the peninsula and establishing a peace regime.

The South Korean negotiator added in such process, close coordination between Seoul and Washington would be the key.