South Korean President Lee Myung- bak left for Shanghai Friday, where he will meet with his Chinese counterpart Hu Jintao and attend the opening ceremony of Shanghai World Expo.

Lee and Hu will discuss strengthening their strategic partnership relations and other current affairs at the summit, where the issue of a mysterious sinking of a South Korean warship is expected to be brought up, Yonhap News Agency said.

The recent naval incident is not part of the official summit agendas but will be naturally discussed, Yonhap said, citing the presidential spokesman Park Sun-kyu.

The two leaders are also expected to discuss a possibility of striking a two-way free trade pact and the upcoming G20 summit among the world's major economies including the two Asian economic powerhouses.

His fifth visit to China coincides with the opening of the Shanghai World Expo.

(Xinhua News Agency April 30, 2010)