Despite pressure from the White House, Powell is widely expected to hold interest rates steady, according to the CME FedWatch Tool, a measure of market sentiment. The central bank's benchmark interest rate currently stands at an elevated level of between 4.25% and 4.5%.

Fed decision day means putting the tense relationship between President Donald Trump and Fed Chair Jerome Powell on full display.

The Fed is expected to leave interest rates unchanged Wednesday, choosing caution as President Trump’s trade upheaval rattles markets and clouds the outlook for inflation and growth.