South Korean President Lee Myung-bak announced Thursday, during a visit to state-run Agency for Defense Development, that Seoul needs the capability to defend its interests.
"Strong (weapons) capabilities are needed to maintain peace, but their purpose lies not in destruction, but in realizing peace and deterring war," he was quoted by the Yonhap news agency as saying."If we are strong, (North Korea) cannot make provocations. North Korea makes provocations when we are weak."
North Korea, after a failed rocket launch last week, said it viewed joint U.S.-South Korean military exercises in the region as an aggressive act.
Pyongyang called on the South Korean government to issue a formal apology for what it said was a defamation of festivals honoring North Korean founder Kim Il Sung.
North Korea said, through its official Korean Central News Agency, that it would launch a "sacred war to wipe out the group of traitors unless South Korea immediately apologize(s)."
North Korea's rocket launch was seen as a violation of U.N. Security Council resolutions prohibiting intercontinental missile tests. A ban in exchange for substantial food assistance from the United States collapsed after the launch.
North Korea is believed to be preparing to test a nuclear device.