The Federal Reserve's first rate hike in three years has exposed new tensions between President Donald Trump and Kevin Warsh, his handpicked Fed chairman. Trump suggested Warsh effectively had permission to support the increase despite considering it the wrong move, saying the chairman lacked enough votes on what he called a hostile rate-setting committee. The comments prompted criticism from former officials and market analysts, who said the Fed chair does not need presidential approval and that the committee appeared united behind Warsh. The episode has renewed concerns about whether Warsh is independent and risks portraying him as unable to lead the committee. Warsh defended the Federal Reserve's independence while declining to discuss his communications with Trump. The relationship is likely to be shaped by inflation, borrowing costs, the S&P 500 and Treasury rates, with some economists warning that continued rate increases could bring the relationship closer to Trump's earlier conflict with former Fed Chair Jerome Powell.