A former commander of the U.S. Forces Korea has called for a strong, "asymmetrical" retaliation against North Korea in the event of further provocations against the South and a halt to all contact with the reclusive regime.
North Korea shelled an island near its disputed border with the South last week, killing two marines and two civilians. South Korea on Friday threatened air strikes if the North repeated the attack.
"Next time the North attacks, there should be an immediate and properly measured asymmetric retaliatory military strike by South Korea," Burwell Bell, who retired in 2008, was quoted by Yonhap news agency as saying.
"Allowing North Korea to attack the South with no counter-strike consequences sends a message of weakness and timidity to Kim Jong-il," he added, referring to the North's leader.
North Korea attack the island of Yeonpyeong and its surrounding waters with 170 artillery shells, to which the South retaliated with 80 rounds minutes later.
Bell urged allies to suspend all ties with the North through "total economic sanctions" and an abandonment of the six-party talks aimed at dismantling the North's nuclear programme.
North Korea walked out of the talks, bringing together the two Koreas, host China, the United States, Japan and Russia, two years ago.
"As long as Kim Jong-il is in power, the six-party talks process is dead, and both the United States and the Republic of Korea (South Korea) should give the talks an official funeral," Bell said, also criticising China for not reining in its ally.
The foreign ministers of the United States, Japan and South Korea, long-time allies, meet in Washington on Monday to discuss North Korea.
China, pushing for an emergency meeting of the six parties, is not going. That means the discussions in Washington have little chance of breaking the impasse.