Top Pentagon officials have provided a detailed assessment to a U.S. Senate committee that a North Korean torpedo caused the sinking of the Cheonan naval ship.

U.S. Assistant Secretary of Defense for Asian and Pacific Security Affairs Wallace Gregson said that a multinational investigation decisively concluded that a torpedo from a North Korean submarine produced a shockwave and bubble jet effect that split open the hull of the Cheonan and sank it almost immediately. He made the remark in a prepared statement to the Senate Armed Services Committee on Thursday.

Also in a prepared statement to the committee, Commander of U.S. Forces Korea General Walter Sharp said that in the aftermath of the Cheonan incident, the South Korean government acted in a responsible manner and led a joint civilian-military investigation to determine the cause of the Cheonan’s sinking that included experts from foreign governments.

He said the group's investigation was performed in an objective, scientific, thorough, and deliberate manner, concluding that North Korea was responsible for the ship’s sinking.