U.S. Secretary of State Hillary Clinton has said North Korea must face consequences for sinking a South Korean warship.

Speaking in Tokyo Friday, Clinton said America, Japan, South Korea and China will respond to the finding that North Korea killed 46 South Korean sailors.

She said it was "important to send a clear message to North Korea that provocative actions have consequences," even though discussing the next step or action in response was "premature."

"The evidence is overwhelming and condemning. The torpedo that sunk the Cheonan...was fired by a North Korean submarine," she told reporters.

The White House called it an unspeakable act of aggression.

"We certainly support the findings of the South Korean investigation," Secretary of Defense Robert Gates. "The attack was against one of their ships and naturally they would have the lead in determining the path forward."

North Korea has called the investigation a fabrication.