By Joshua Mitnick

HERZLIYA, Israel---Federal Reserve Vice Chairman Stanley Fischer said Monday the central bank expects to follow a "gradual and relatively slow" trajectory of short-term interest-rate increases over the next three to four years to bring borrowing costs back to "normal" levels.

Mr. Fischer said observers focus too much on when the Fed will start raising its benchmark short-term rate from near zero, and instead should think more about where interest rates are headed over time. He said Fed economists expect the rate will reach from 3.25% to 4% in three to four years.

"There is so much importance given to the first move. But I think it's misleading," said Mr. Fischer in a lecture at the Interdisciplinary Center Herzliya, a college in a suburb outside Tel Aviv.

Mr. Fischer, who served as chief of Israel's central bank for eight years before becoming the No. 2 U.S. central banker, said the coming Fed rate increases "will be a gradual process."

He said it would not be like the relatively rapid and predictable path of Fed rate increases from 2004 to 2006, when the benchmark rate rose by 0.25 percentage point at each of 11 consecutive monetary policy meetings.

His comments echoed those of Fed Chairwoman Janet Yellen, who said Friday the central bank is on track to raise interest rates this year but will likely proceed cautiously because the job market hasn't fully healed, inflation is low and growth has again disappointed.

The Fed has held its benchmark federal funds rate near zero since late 2008. Mr. Fischer noted many investors and economists think the central bank is likely to start raising it in September.

He said the timing for the first rate increase would depend on the pace of economic growth, he said. "Our process is not date-determined. They are data-determined," he said "We will wait and see what happens. If the economy is moving slow we'll wait. If fast, we'll do it earlier."

He said the frequent references to the coming first rate increase as "liftoff" was something of a misnomer. "You say liftoff and you think of rockets" that go into orbit after 10 seconds, he said. "That's not what we're talking about."