The two countries signed a bilateral investment treaty (BIT) on their US$4-billion project to build a chemicals plant and develop a gas field in the Uzbek region of Surgil, South Korea’s presidential office said.

In their summit here, President Lee Myung-bak [Ri Myo’ng-pak] and his Uzbek counterpart Islam Karimov agreed that the signing of the BIT on the Surgil project is the latest symbol of the two countries’ closer partnership. Karimov arrived here on Wednesday on a three-day trip to reciprocate Lee’s trip to Tashkent in May last year.

"The leaders expressed satisfaction over the consistent development of the two countries’ relations in various fields including politics, economy, and culture, and reaffirmed their will to make joint efforts to deepen a strategic partnership," read a joint press release issued after the summit.

Lee and Karimov welcomed the signing of the BIT on the Surgil project and fresh deals on joint exploration of oil fields in West Fergana and Chinabad in Uzbekistan, it added. South Korea and Uzbekistan are already working together to explore the Namangan and Chust oil fields.

Energy-rich Uzbekistan has emerged as South Korea’s major economic partner. South Korea, a leading Asian economy, imports 97% of its energy and minerals needs.

"The leaders also agreed to boost cooperation on the green growth sector including the Compressed Natural Gas (CNG)," the joint statement said. The CNG, a fossil fuel, is environment-friendly substitute for gasoline, diesel, or propane fuel.

The South Korean president reaffirmed his pledge to expand official development assistance for the Central Asian country eager to develop the health and medical industry, the education sector, and infrastructure as well as learn South Korea’s experience in rapid economic growth and its macroeconomic policy.

On regional and global issues, they agreed to the importance of the "complete and verifiable denuclearization" of North Korea in Northeast Asian security.

President Karimov expressed support for the South Korean government’s position to resolve the nuclear crisis through the prompt resumption of the six-way talks, according to the joint press release.

The two sides also agreed to join hands for helping reconstruct Afghanistan.