During an interview with CNBC, Trump said that while Federal Reserve Chair Jerome Powell, who took over the role in February, was a "a very good man", he did not like the central bank's recent interest rate hikes.
"As usual, not a level playing field", Mr. Trump wrote.
Higher rates, however, strengthen the dollar against the world's currencies, which makes the United States a more expensive - and potentially less attractive - place to invest. In a tweet Friday morning, the president added that "tightening now hurts all that we have done".
Trump also showed displeasure about the Fed´s monetary tightening, saying that he was anxious about its potential impact on the USA economy and American competitiveness. "I couldn't care less what they say, because my views haven't changed".
In a statement to CNBC, the White House said: "Of course the President respects the independence of the Fed". "I really like President Xi a lot". "We are being taken advantage of and I don't like it".
His allegations that China and the European Union are manipulating currencies are at odds with a Treasury Department report released in April that did not name any country as a currency manipulator.
The Fed has raised the benchmark lending rate twice this year after three increases in 2017 and two more rate hikes are expected this year as the central bank removes stimulus from the economy to keep a lid on inflation.
"I don't want them to be scared".
"All those things point to the Fed continuing to raise interest rates and the economy being fairly strong, relative to all the global issues going on: trade wars, the fear in Europe of Brexit without a clear path". Powell was a governor on the Fed and has largely followed the path the Fed has been on for years, slowly raising interest rates as the economy strengthens, unemployment declines and inflation stirs.
St. Louis Federal Reserve Bank James Bullard said on Friday the Fed would remain unaffected by Trump's comments on monetary policy and expressed concerns about rising tariffs.
Fed Chairman Jerome Powell, who Trump named to lead the USA central bank, said earlier this month he was not concerned about pressure from US politicians.
A picture illustration of USA dollar, Swiss Franc, British pound and Euro bank notes January 26, 2011.
The Fed has been slowly raising interest rates since December 2015 in an effort to avoid overheating the US economy. "We have been ripped off by China for a long time", he said. "His intention is not to in any way put pressure on the Fed", the Treasury Secretary said, referring to the USA central bank.
"I'm ready to go to $500 [billion]", Trump said.