Markets in recent weeks have gained ground amid hopes the Fed would dial back its aggressive interest rate hikes, and perhaps even begin to cut next year.
But with inflation at a 40-year high, officials have drilled home the message that investors should temper those expectations.
Powell is due to deliver his speech at 10:00 am Eastern Time (1400 GMT) at an annual central banking symposium in Jackson Hole, Wyoming.
Upbeat economic data meanwhile continued to trickle in, with the Federal Reserve’s preferred inflation index falling 0.1 percent in July compared to June, according to the Commerce Department.
“The July report brought some welcome news, but it is unlikely to dissuade the Fed — and Fed Chair Powell — from suggesting more rate hikes are needed and that interest rates will probably need to stay higher for longer,” said Briefing.com analyst Patrick O’Hare.
On Thursday, government reports meanwhile showed initial applications for unemployment benefits unexpectedly fell last week, dispelling concerns about a weakening job market.
About 15 minutes into the session, the Dow Jones Industrial Average was up 0.1 percent at 33,314.23.
The broad-based S&P 500 fell 0.1 percent to 4,194.13, while the tech-rich Nasdaq Composite Index slid 0.2 percent to 12,610.91.
In individual stocks, Workday, which creates financial management and human resources software, was up 6.6 percent following a positive quarterly report.
Beauty product chain Ulta Beauty was meanwhile up 2.4 percent after quarterly earnings beat estimates.
