The top nuclear negotiators of South Korea, the U.S. and Japan shared the need to continuously send a “stern” message to deter North Korea’s provocations such as its test of a submarine-launched ballistic missile, during their trilateral meeting on Thursday.

After the meeting in Washington, Seoul’s chief negotiator Hwang Joon-kuk said that the three sides agreed to continue their joint efforts to press Pyongyang to return to the dialogue table for its denuclearization, and enhance the “efficacy” of international sanctions against it.

The trilateral meeting came after the North was spotted digging a new tunnel at its nuclear test site in the country’s northeastern region. The North also recently conducted a test on the SLBM, further escalating nuclear threats.

The meeting was attended by Hwang, U.S. special representative for North Korea policy Sung Kim and Kimihiro Ishikane, a director general at Japan’s Foreign Ministry.

“(The three nations concur that) North Korea should come out for talks, the ‘exploratory talks,” without conditions,” Hwang said in a meeting with reporters.

Seoul has been pushing for what it calls “unconditional” exploratory talks with the communist regime as a pre-step to resume the long-stalled six-party denuclearization talks involving the two Koreas, the U.S., China, Japan and Russia.

Pyongyang has so far refused to respond to the overtures, while calling itself a nuclear power in its constitution and through various media statements.

Touching on the 2005 joint statement from the six-party talks, in which the North agreed to a set of denuclearization steps, Hwang urged Pyongyang to stop nuclear and missile tests, freeze its nuclear activities and accept inspectors from the International Atomic Energy Agency. He called these procedures a “starting point” to fulfill its past commitments.

As for a “new element” in the efforts to denuclearize North Korea, Hwang said that while Seoul and partner nations continue to maintain a two-track stance employing both dialogue and pressure, they would explore various other options “depending on situations.”

By Song Sang-ho (sshluck@heraldcorp.com)