Federal Reserve Chairman Jerome Powell delivered a strict commitment Friday to curbing inflation, warning that he expects the central bank to continue hiking interest rates in a way that will cause “some pain” to the U.S. economy.

In his annual policy speech at Jackson Hole, Wyoming, Powell said that the Fed will “use our tools forcefully” to halt inflation, still running near its highest level in more than 40 years.

Even with a series of four consecutive interest rate hikes totaling 2.25 percentage points, Powell said this is “no place to stop or pause” even though benchmark rates are probably around an area considered neither stimulative nor restrictive to growth.

“While higher interest rates, slower growth, and softer labor market conditions will bring down inflation, they will also bring some pain to households and businesses,” he said in prepared remarks. “These are the unfortunate costs of reducing inflation. But a failure to restore price stability would mean far greater pain.”

Stocks plunged after the Powell speech, with the Dow Jones Industrial Average off more than 500 points. Treasury yields were off their highs of the session.

The remarks come amid signs that inflation may have peaked but is not showing any marked signs of decline.

Powell cautioned that the Fed’s focus is broader than a month or two of data, and it will continue pushing ahead until inflation moves down closer to its 2% long-range goal.

“We are moving our policy stance purposefully to a level that will be sufficiently restrictive to return inflation to 2%,” he said. Looking into the future, the central bank leader added that “restoring price stability will likely require maintaining a restrictive policy stance for some time. The historical record cautions strongly against prematurely loosening policy.”

“In essence, Powell is clearly stating that right now, fighting inflation is more important than supporting growth,” said Jeffrey Roach, chief economist at LPL Financial.