US President Donald Trump ratcheted up his pressure on the Federal Reserve, saying that if the central bank had "not mistakenly raised interest rates," the US gross domestic product would be higher and markets "would be in a better place."

The president's comment, in a Twitter post on Friday afternoon, was yet another shot across the bow of Fed Chairman Jerome Powell, who Trump has repeatedly rebuked since the Fed raised borrowing costs four times last year.

Trump even discussed firing Powell, Bloomberg News reported in December.

Earlier on Friday, White House chief economic adviser Larry Kudlow called on the Fed to "immediately" cut interest rates by a half percentage point, escalating the Trump administration's fight with the central bank and challenging its independence.