Authoritative economist Jeremy Siegel criticized the Federal Reserve for hitting the brakes too hard by raising interest rates too high in an attempt to beat inflation.

If they continue to raise rates even early next year, the risks of a recession are extremely high, he told CNBC.

Siegel, a professor at the Wharton School of Business at the University of Pennsylvania, said he was one of the first to warn the Fed in 2020 and 2021 about a possible rise in inflation and that the Fed should have started tightening its monetary policy much earlier. But now he fears it's too late to stop a recession in the U.S. economy.

The Fed has raised interest rates five times this year - the last three hikes were 75 basis points each from 3 percent to 3.25 percent,.

Inflation slowed year-over-year from 9.1% in June to 8.5% in July and then to 8.3% in August. But that's not enough for the Fed, which has indicated that it will likely continue to raise rates, with another 75 basis point increase expected in November. This comes despite growing concern among investors and economists that rapid and aggressive rate hikes are causing a recession in the economy.

The September employment report showed that employers slowed hiring, which may indicate that the Fed has somewhat succeeded in slowing the economy. But at the same time, the unemployment rate has fallen, which may give the Fed more room to raise rates again.

Siegel argued, however, that inflation should not be the main concern at this point. "Most of the inflation is behind us, and the biggest threat today is recession, not inflation," he said, noting that official data do not immediately show what is happening in the real world.

Current interest rates, according to Siegel, are sufficient to bring inflation down to 2%, which is the Fed's goal.

For his part, Fed Chairman Jerome Powell made it clear that despite the pain for households and businesses, he is committed to lowering inflation, and for him that means raising interest rates