South Korean President Lee Myung-bak said Monday his country will resort to measures of self-defense in case of further military provocation from the Democratic People's Republic of Korea (DPRK), calling Pyongyang's alleged sinking of its warship in late March work of a surprise torpedo attack.

"North Korea (DPRK) will pay a price corresponding to its provocative acts. I will continue to take stern measures to hold the North accountable," Lee said in a nationally televised speech to the public, a few days after an international team of experts concluded that South Korea's 1,200-ton corvette Cheonan was torpedoed by its wartime rival.

The president said DPRK-flagged ships will no longer be allowed to make passage through any of the shipping lanes in South Korean waters, which was previously permitted under the Inter-Korean Agreement on Maritime Transportation.

Seoul, calling cooperation with DPRK "meaningless," said it will also put trade and exchanges between the two Koreas on hold, although it plans to continue its humanitarian aid to Pyongyang.