The comments Thursday came during a meeting of top government officials aimed at reviewing security and economic impacts of the exchange of fire Tuesday that left four South Koreans dead and the region on edge.
Yonhap news agency reported that South Korean President Lee Myung-bak ordered his officials to beef up security around islands off South Korea's western coast.
Pyongyang, meanwhile, is lashing out against the United States and South Korea, warning of more retaliation if Seoul carries out "reckless military provocations."
South Korea Raises Security After North Korea Attack
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