U.S. Secretary of State Hillary Clinton is expected to stress to China the severity of the sinking of the South Korean warship Cheonan and the importance of a joint response with Beijing.

Clinton is visiting China, and news reports quoted a top U.S. official accompanying her as making this comment.

The official says Clinton will tell reporters in Shanghai why the Cheonan incident is a serious matter and why inducing Chinese cooperation is needed.

South Korea announced Thursday that a North Korean torpedo attack sank the naval vessel.

The Washington Post also says Washington officials accompanying Clinton to Beijing do not believe Seoul is considering a military response to Pyongyang's attack.