Kevin M. Warsh, the Federal Reserve chairman, said the bank acted to fight inflation that 'is too high and has been for too long.' He declined to discuss whether the rate increase on Wednesday was the first of a series of moves or just a one-off.

The Federal Reserve raised rates by a quarter of a percentage point on Wednesday to a range of 3.75 percent to 4 percent. The decision was unanimous, which Mr. Warsh repeatedly mentioned in a news conference as evidence that the central bank was resolute in its commitment to getting inflation down.

Mr. Warsh declined to discuss whether this rate increase was the first of a series of moves or just a one-off, which would be unusual for the Fed. Instead, he said the move was about 'removing a dose of accommodation so that financial and credit conditions would be more consistent' with the Fed's goals of low, stable inflation. Given his assessment that the economy is on solid footing, coupled with officials' new forecasts that show a slower retreat in inflation, this is unlikely to be the last adjustment from the Fed. In fact, new projections showed broad support on the Fed for at least one more increase this year.

Rising U.S. borrowing costs have been a focal point not just for the Trump administration, but also for Fed policymakers. Asked about what was driving the rise, Mr. Warsh pointed to not only higher growth prospects for the economy but to more competition for capital as technology companies borrow heavily to finance the expansion of their artificial intelligence capabilities. Importantly, he did not convey that concerns about inflation were behind the recent moves in the bond market, which have been sharp enough to prompt Treasury Secretary Scott Bessent to intervene in a variety of ways. Mr. Warsh demurred from any questions related to President Trump, who has made clear his desire for lower rates. Just days before the meeting, Mr. Trump threatened to cut off broad swathes of trade with other nations if the Fed did not cut rates. But as the Fed's move on Wednesday shows, inflation is too big of a problem for policymakers at this juncture to entertain doing anything other than holding rates steady or raising them.