US inflation is "still too high" despite a recent slowdown, Federal Reserve Chair Jerome Powell said on Thursday, leaving the door open for a new interest rate hike.

Additional evidence of "persistently above-trend growth," or fresh signs of tightness in the labour market, "could warrant further tightening of monetary policy," he told a conference in New York, according to prepared remarks.

The Fed recently slowed its aggressive campaign of monetary tightening which lifted its benchmark lending rate to a 22-year high, as it looks to slow down inflation without pushing the US economy into recession.

Headline inflation, as measured by the Fed's favoured gauge, has fallen by more than half since peaking in June last year, but remains stuck above its long-term target of two percent.

"Inflation is still too high, and a few months of good data are only the beginning of what it will take to build confidence that inflation is moving down sustainably toward our goal," Powell said.

"We cannot yet know how long these lower readings will persist, or where inflation will settle over coming quarters," he continued, adding that the Fed would proceed "carefully."

Futures traders currently assign a probability of more than 95 percent that the Fed will announce it is hold interest rates steady on November 1, following its next meeting, according to data from CME Group. (AFP)