Donald Trump has lashed out at the Federal Reserve after it defied his demands and hiked interest rates for the first time in three years. The Fed unanimously raised its benchmark rate by a quarter point to 3.75-4 per cent as officials battle stubbornly elevated inflation. Trump immediately fired back, declaring US interest rates should instead be slashed to 1 per cent or less. Fed officials warned inflation remains elevated and signalled another rate hike could come this year despite Trump demanding dramatically cheaper borrowing. The extraordinary clash puts Trump at odds with Fed Chair Kevin Warsh, whom the president hand-picked to lead the powerful central bank.