South Korea, the United States and Japan agreed Wednesday to ratchet up pressure and sanctions on North Korea, while continuing efforts to bring the communist nation back to talks.

Top nuclear envoys of the regional powers, in a Seoul meeting, concurred that advancement in the North's nuclear capability is "serious" and shared a "sense of urgency" in addressing the problem.

"In order to deal with it, (we) agreed to put stronger pressure (on Pyongyang) and make active efforts for dialogue," Hwang Joon-kook, Seoul's senior diplomat in charge of North Korea affairs, told reporters.

He was briefing the results of the three-way discussions with his American and Japanese counterparts -- Sung Kim and Junichi Ihara.

The gathering, the first of its kind in four months, came as Pyongyang refuses to return to the negotiating table and instead has continued its provocative acts.

It recently announced the successful test-launch of a ballistic missile from a submarine and significant progress in miniaturizing nuclear bombs.

The secretive regime, led by Kim Jong-un, who is in his early 30s, also reportedly purged defense minister Hyon Yong-chol.

Hwang said the envoys agreed to the "seriousness in advancement in North Korea's nuclear capability."

He also warned the North that it will face more international pressure if it stays on the current course.

"North Korea's diplomatic and economic isolation will deepen," he said.

U.S. envoy Sung Kim echoed the view.

"We agreed on the importance of enhancing pressure and sanctions on North Korea even as we keep all diplomatic options on the table and open," he said. "We agreed that we should be exploring all opportunities to increase pressure in terms of better, stronger implementation of existing sanctions but also looking at all other opportunities and avenues to increase pressure."

He added that the three nations reaffirmed their commitment to continuing the "closest possible trilateral coordination" on North Korea and also maintaining "five-party unity," including China and Russia.

They all are members of the six-way talks on the North's nuclear program. The Beijing-based negotiations have been dormant for more than six years.

The Japanese delegate, Ihara, said the three parties, based on the "sense of urgency," had in-depth discussions on ways to handle the North's nuclear and missile programs.

"We were able to confirm that the three countries have the same perception," he said.

Meanwhile, Hwang plans to visit Beijing on Thursday to meet China's top nuclear negotiator, Wu Dawei, and share the results of the tripartite discussions in Seoul.

Kim will also meet separately with Wu in the Chinese capital the same day.

"I think the Chinese understand that as chair of the six-party process, they have a special responsibility to get the North Koreans to work with us towards denuclearization," he said. "I expect to have full consultations with Ambassador Wu Dawei tomorrow on how the Chinese may engage the North Koreans to bring the North Koreans to some credible and authentic negotiations." (Yonhap)