Wall Street shares rallied Friday as US Federal Reserve chief Jerome Powell left the door open to cutting interest rates.

Investors had been eagerly waiting for Powell's speech all week, hoping for hints that the Fed would cut rates at its next meeting in September to spur economic growth.

New York's three main indexes surged following his remarks, rebounding after a tech sell-off this week.

European stock markets also advanced in afternoon deals, though the focus there was also on the impact of President Donald Trump's tariffs on the German economy, which shrank in the second quarter.

In his speech at the annual symposium of global central bankers in Jackson Hole, Wyoming, Powell warned that risks of higher inflation and a weakening jobs market meant a "challenging situation".

"Downs

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