The U.S. National Security Council is stressing that evidence is being objectively assessed in order to determine the cause of the sinking of the “Cheonan.”

The council’s spokesman, Mike Hammer, told KBS Friday that a probe to determine what caused the naval ship to sink is being carried out carefully and methodically.

He stressed that evidence is being collected, analyzed, and objectively assessed by the team of investigators.

However, Hammer refused to comment on rumors that North Korea might be involved in the sinking of the ship, saying questions regarding such rumors should be addressed to the South Korean government.