N. Korea: We'll Retaliate if Provoked

South Korea's president is vowing to boost security around islands near the site of this week's artillery attack by North Korea.

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.

North Korea, meanwhile, lashed out at the United States and South Korea, warning of more "retaliation" if Seoul carries out any "reckless military provocations."

Yonhap news agency says South Korean President Lee Myung-bak ordered his officials to beef up security around islands off South Korea's western coast.

Obama: We Will Defend South Korea
S. Koreans Recount Attack; 2 More Bodies Found

The bombardment Tuesday of a tiny South Korean island along a disputed maritime frontier killed at least four people, including two civilians, sparked a brief skirmish and alarmed world leaders including President Barack Obama, who reaffirmed plans for joint maneuvers with Seoul in the Yellow Sea starting Sunday.

The North made no specific mention of the joint military exercises involving the aircraft carrier USS George Washington. But, it warned, its "military will launch second and third strong physical retaliations without hesitation if South Korean warmongers carry out reckless military provocations."

The North's statement said Washington was to blame for South Korean artillery exercises earlier in the week near disputed waters which prompted the North to respond with its artillery barrage on Yeongpyeong island Tuesday.

Washington "should thoroughly control South Korea to ensure they won't continue adventurous military provocations" such as violation of the countries' disputed sea border, it said.

The warning was issued by North Korea's military's mission at the truce village of Panmunjom and was carried by the country's official Korean Central News Agency.