WASHINGTON, Sept 11 (Reuters) - U.S. President Donald Trump on Wednesday said the Federal Reserve should lower U.S. interest rates to "zero or less" to help "refinance our debt" with lower interest costs and a longer term, and blamed the U.S. central bank's chief for missing "A once in a lifetime opportunity".

"The USA should always be paying the ... lowest rate. No Inflation! It is only the naïveté of Jay Powell and the Federal Reserve that doesn't allow us to do what other countries are already doing," Trump wrote in a pair of early morning tweets. (Reporting by Susan Heavey; Editing by Catherine Evans)