President Trump called on the U.S. Federal Reserve Wednesday to lower interest rates to negative territory so that the federal government could refinance its $22 trillion debt and called the leaders of the central bank “boneheads.”

In a series of tweets, Trump said lowering interest rates would keep inflation low and cited actions in other countries that already have negative interest rates.

“It’s only the naivete of Jay Powell and the Federal Reserve that doesn’t allow us to do what other countries are already doing,” Trump tweeted. “A once-in-a-lifetime opportunity that we are missing because of ‘boneheads.’”

JP Morgan CEO Jamie Dimon said banks already are preparing should interest rates go to zero or lower. He said banks likely would come up with new fees, perhaps even charging customers for deposits, the Wall Street Journal reported.

The Fed’s Federal Open Markets Committee meets next Tuesday and Wednesday and is expected to lower interest rates 25 basis points. The rates at which banks borrow money from each other currently are set at 2% to 2.25%. The last rate reduction was at the FOMC’s July meeting, the first such move in 11 years.

Trump has expressed dissatisfaction with Fed Chairman Jerome Powell and has tried to pressure him into following the White House’s lead. He blames the Fed for a slowing economy. Powell last week reiterated the Fed’s apolitical stance and said the central bank would not succumb to political pressure.

In fiscal 2018, the average interest rate on the public debt was nearly 2.5% and net annual interest payments totaled $393.5 billion. That grew to $538.6 billion this year. The debt itself has grown $2.6 billion on Trump’s watch, largely due to the 2017 tax cuts.

Mark Zandi, chief economist at Moody’s Analytics, told CNBC refinancing the national debt “could be a significant problem for investors, financial markets and ultimately the economy” because there’s no prepayment option.

“I think it would be incredibly disruptive to financial markets, and interest rates would ultimately rise, not fall,” he said.

Treasury Secretary Steven Mnuchin recently mused about issuing longer term bonds in the 50- to 100-year range.

Trump is the first U.S. president to promote interest rates below zero. The Fed is reluctant to make such a move because it would give the central bank little room to maneuver should the economy fall into recession when lowering interest rates is a tool used to boost growth. Experts said negative rates would make investment in U.S. Treasurys less desirable.

The European Central Bank has negative interest rates and that has made it difficult for European banks to make profits. The ECB is expected to cut rates a further 10 basis points at its meeting Thursday.