Evans, who has long argued for a delay to rate hikes so as not to undermine economic recovery, said that the U.S. central bank should not move on rates until there was greater confidence that its inflation goal could be hit within one or two years.

"Inflation is too low," Evans told an audience in Munich. "The FOMC (Federal Open Market Committee) should refrain from raising the federal funds rate until there is much greater confidence that inflation one or two years ahead will be at our 2 percent target."

"It likely will not be appropriate to begin raising the Fed funds rate until some time in early 2016," said Evans, who is a voter this year on Fed policy and among the most dovish of U.S. central bankers.

Evans argued for rates to start rising in early 2016 in a speech in Stockholm on Monday, though he also said the Fed could look at a hike in June if the economy was strong enough.

Nearly all of his peers, including Fed Chair Janet Yellen, believe an interest rate hike will be appropriate some time this year, although the exact timing is up for debate.

The Fed's policymaking Federal Open Market Committee meets next on June 16-17.