BEIJING - The Democratic People's Republic of Korea (DPRK) has rejected a demand by the Republic of Korea (ROK) on Monday that Pyongyang apologize for the sinking of one of its warships.

ROK President Lee Myung-bak also said that his country will take the issue to the UN Security Council and resort to self-defense measures in case of "further military provocation" by the North.

"I solemnly urge the North Korean (DPRK) authorities ... to apologize immediately to the Republic of Korea and the international community," Lee said in a nationally-televised speech.