Wharton professor Jeremy Siegel has warned the Federal Reserve is highly aggressive with its monetary policy, creating an extremely high risk of the US economy tumbling into a recession.

"The Fed is slamming on the brakes way too hard," Siegel said in a CNBC interview on Friday, referring to the central bank rapidly hiking interest rates this year in a bid to curb raging inflation. It was too late to the game and should have started tightening its monetary policy much earlier, he added.

Inflation soared to a 40-year high in June, coercing the Fed officials to launch three consecutive rate hikes of 75 basis points in recent months. The central bank has now hiked its benchmark rate to a range of 3% to 3.25% and signaled more increases in the coming months.

However, the Fed risks going too far, Siegel said. "The pendulum has swung too far in the other direction," he argued, adding that he now views recession as a greater concern than inflation.

"If they stay as tight as they say they will, continuing to hike rates through even the early part of next year, the risks of recession are extremely high," Siegel said. He asserted that much of the rapid price growth is over, but inflation will appear elevated in official statistics for a while as economic data lags reality.

"The biggest threat is recession, not inflation today," he added.