Joint investigation committee concludes North Korea sunk Cheonan

A joint investigation committee announced Thursday morning in Seoul that they had concluded a North Korean submarine fired a torpedo that sank the South Korea warship in March. The committee comprised of American, Australian, British and Swedish, as well as South Korean, experts.

"(We) will take resolute countermeasures against North Korea and make it admit its wrongdoings through strong international cooperation and return to the international community as a responsible member," South Korean President Lee Myung-bak told Australian Prime Minister Kevin Rudd in phone talks, according to Lee's office, Yonhap reported.

The North Korean National Defense Commission said in a statement to official television that its navy did not torpedo the South Korean ship, calling South Korean President Lee "a traitor," Yonhap reported.