South Korea's president has made an emotional pledge to find answers in last month's sinking of a navy warship.  He vowed that the victims of the sinking will not be forgotten, and those responsible will face "resolute" action.  

South Korean President Lee Myung-bak tearfully named each of the 46 sailors who lost their lives in last month's sinking of the Cheonan, a South Korean naval vessel.

Monday's nationally televised address was relatively rare for the South Korean leader, who often delegates officials to communicate on his behalf.  

Mr. Lee's voice cracked with emotion as he vowed a complete investigation.

He says as president, he promises he will find out the cause of the Cheonan sinking in full detail, then deal with it in a firm and resolute way.  He vows never to allow such an incident to happen again.

One hundred and four sailors were aboard the Cheonan when an apparent explosion split the vessel in two and sank it in waters west of the Korean peninsula.  

North and South Korea have fought three past naval clashes in the area, where Pyongyang has long rejected a United Nations-imposed maritime border.

The head of a multinational investigative team said last week he thinks an "external explosion" damaged the ship, fueling widespread speculation it was caused by a North Korean torpedo or mine.

On Saturday, North Korea angrily denied any role in the sinking.

A North Korean announcer reads a government statement accusing South Korea of a "foolish ruse" to cover its own failure to explain the sinking.

President Lee made no direct mention of North Korea in Monday's address, and his cabinet officials have steered clear of outright accusations directed at the North.

However, a North Korean role is by no means ruled out.  South Korea's foreign minister on Sunday said in a television interview that Seoul will seek an international response if evidence points conclusively to a North Korean attack. Among other things, he said, the government would take the matter to the United Nations Security Council.