Chinese shares opened lower on Friday ahead of U.S. Federal Reserve Chair Kevin Warsh's Jackson Hole speech.

The Shanghai Composite Index, the main gauge of Chinese stocks, declined 0.2% to 3,950.24. The Shenzhen Component Index edged down 0.2% to 14,019.28.

The market is awaiting Warsh's speech for fresh clues on the U.S. rate outlook, keeping investors cautious.

Market sentiment was also dampened by renewed U.S.-China tensions over Iran-related sanctions and concerns about elevated valuations in technology stocks.