Leaders of South Korea and Thailand urged North Korea on Saturday to call off its plan to launch a long-range rocket, saying the move hurts regional peace and violates a U.N. Security Council resolution.

The appeal came after summit talks between President Lee Myung-bak and Thai Prime Minister Yingluck Shinawatra. Yingluck arrived in Seoul earlier in the day for next week's global anti-nuclear terrorism conference.

"We agreed that North Korea's long-range rocket launch plan is a threat to regional peace and stability and North Korea should halt the launch and abide by a U.N. Security Council resolution,"

Lee said during a joint news briefing with Yingluck.

Lee also said he and the Thai leader also shared an understanding that it is a "self-contradiction" for a nation whose people are suffering from hunger to go ahead with a rocket launch that costs an enormous amount of money.

The anti-nuclear conference in Seoul comes amid heightened tensions over North Korea's announcement last week that it will launch a long-range rocket next month to put what it claimed is a satellite into orbit, a long-running pretext that the provocative regime has used to disguise banned missile tests.

On bilateral issues, Lee and Yingluck agreed to boost defense cooperation, deepen all-around cooperation and upgrade their relations to a "strategic partnership" in the near future, a joint statement said.

On the sidelines of the summit, the defense ministers of the two countries signed a memorandum of understanding that lays out the scope and other details and principles on defense exchanges.

The presidential office said the accord is an instrumental basis for defense cooperation.

Lee and Yingluck welcomed the agreement and pledged to work closely together to further accelerate and deepen cooperation, especially in the areas of disaster relief and peacekeeping, the joint statement said.

The two leaders also agreed to cooperate actively to establish a water resources management system in Thailand, which suffered devastating flooding last year. The sides agreed to sign a memorandum of understanding on technical cooperation in water management, the statement said.

The Thai leader has expressed high interest in South Korea's project to refurbish four major rivers in a way that prevents floods, preserves water resources and promotes tourism along the waterways. She is scheduled to visit project sites while in South Korea.

Lee and Yingluck appreciated that the two countries' relations have steadily become more friendly and cooperative since they forged diplomatic ties in 1958, and agreed to make joint efforts to lift the relations to a "strategic partnership," the statement said.

They welcomed the increase in bilateral trade volume to the all-time high of US$13.9 billion last year, and made further efforts to boost trade volume to $30 billion within the next five years by 2016, the statement said.

Yingluck expressed gratitude to Lee for South Korea's swift provision of relief aid during last year's flooding in Thailand, and praised Lee for his "low carbon, green growth" drive aimed at seeking economic development through environment friendly industries. (Yonhap News)