San Francisco Fed President John Williams said in an interview with CNBC on Monday that the Fed's interest rate decision will depend on the incoming economic data, adding that he was concerned about low inflation.

He also said that the Fed would not introduce negative interest rates.

Williams noted that the global financial and economic developments abroad had an impact on the U.S. economy and the Fed's monetary policy, saying the U.S. economy was doing well.

Williams is not a voting member of the Federal Open Market Committee (FOMC) this year.