"Economic numbers looking REALLY good. Can you imagine if I had long term ZERO interest rates to play with like the past administration, rather than the rapidly raised normalized rates we have today. That would have been SO EASY! Still, markets up BIG since 2016 Election!" Trump wrote in an early morning tweet.

Federal Reserve Chairman Jerome Powell on Friday said he would not resign even if President Donald Trump asked him to do so, a clear assertion of the U.S. central bank's independence in the face of Trump's strident criticism of the Fed's rate hikes.

Legal experts say it is not clear whether Trump could in fact dismiss Powell.

After the Fed's decision in mid-December to raise rates for a fourth time in 2018, reports surfaced that Trump had discussed with his advisors the feasibility of firing Powell.

Trump in the final months of 2018 repeatedly attacked the Fed, blaming market volatility on the central bank's steady and gradual interest-rate increases and calling it the "only problem" for the U.S. economy.

(Reporting by Lisa Lambert; Writing by Nick Zieminski)