A diplomatic source in Washington said Thursday South Korea, the United States and Japan agreed on the need to resume multilateral talks on resolving the North Korean nuclear crisis as early as possible.

Seoul's Deputy Foreign Minister Lee Soo-hyuck, U.S. Assistant Secretary of State James Kelly and Mitoji Yabunaka, director-general of the Japanese Foreign Ministry's Asian Affairs Bureau, held a second round of talks in the U.S. capital aimed at agreeing on the details of a blueprint designed to persuade Pyongyang to abandon its nuclear ambitions.

The first round of talks were held on Tuesday.

The source said the three officials agreed that the early resumption of multilateral talks on the nuclear issue was necessary to dismantle the North's nuclear weapons program in a complete and verifiable manner.

The source added that discussions were focused on the three countries' measures concerning possible five-way talks to resolve the North Korean nuclear issue.

The ongoing nuclear standoff began in October of last year, when the U.S. claimed the North was operating a secret nuclear weapons program in violation of a 1994 accord.