U.S. stock index futures were higher Friday morning, as market participants awaited a key speech from the Federal Reserve's top official.

At around 04:00 a.m. ET, Dow futures rose 84 points, indicating a positive open of more than 68 points. Futures on the S&P and Nasdaq were both slightly higher.

Market focus is largely attuned to the U.S. central bank's annual Jackson Hole symposium, with Fed Chairman Jerome Powell expected to address an audience of policymakers and economists at around 10:00 a.m. ET.

Powell faces the tough challenge of presenting a unified voice on Fed policy from the most divided U.S. central bank in years.

It comes as both the Fed and Powell are under an unprecedented siege from an angry president, while a speech that fails to assure investors the U.S. central bank will continue to cut interest rates could create even more market volatility.

Source : CNBC