Federal Reserve Vice Chairman Stanley Fischer said it was "misleading'' to give so much importance to the Fed's first interest rate hike since the process of returning to a more normal level will take a few years.
Fischer, speaking in Israel, said that while markets largely expect the first rate hike in September, it will be determined by data and not by date.
"If the (U.S.) economy is growing very, very slowly we will wait. If the economy is growing faster we will do it quicker,'' he said in a speech.
"What we are thinking about is raising the interest rate from zero, which is an ultra expansionary monetary policy to a quarter percent, which is an extremely expansionary monetary policy. This will be a gradual process,'' he said.
Fischer noted that the Federal Reserve board expects the interest rate will reach 3.25 to 4 percent by 2017-2018.