Speaking about his decision to pick Powell to replace Janet Yellen earlier this year, Trump said, "I put a man in there who I like and respect." But he also said, "we are not being accommodated" by the Fed's string of rate hikes.

"I don't like that," Trump said in an interview with Bloomberg News.

Trump has previously complained that the Fed's rate hikes are hurting his efforts to boost economic growth and also driving up the value of the dollar, which hurts U.S. exports.

The president said that the central banks of other nations are helping their governments on the trade front but the Fed is not.

"That being said, I'm not sure the currency should be controlled by a politician," Trump said.

The president's remarks came after Treasury Secretary Steven Mnuchin on Tuesday praised Powell as a "phenomenal leader" at the Fed.

In an interview with CNBC, Mnuchin said he respects the Fed's independence and he believes Powell understands the need for economic growth and will therefore be careful in implementing monetary policy.

In a string of comments and tweets starting in late July,  Trump has expressed his unhappiness with the Fed's rate hikes, saying they could threaten the stronger economic growth he is trying to achieve with his economic program of tax cuts and deregulation, saying in one interview he was "not thrilled" with the rate hikes.

Mnuchin said he meets with Powell on a weekly basis, continuing a long-standing practice of weekly discussions between Fed leaders and the Treasury secretary.

"I think he understands the issue of growth and he's carefully monitoring the growth numbers and the inflation numbers," Mnuchin said.

In a speech last week at the Fed's annual policy conference in Jackson Hole, Wyoming, Powell signaled that the Fed is still on track to keep raising interest rates at a gradual pace. The Fed has raised rates twice this year so far and signaled that it plans to hikes rates two more times in 2018.