Trump has been highly critical of Fed chair Powell for not cutting rates. Some see Trump's pressure campaign against the central bank chief as futile.

Jerome H. Powell, whose term does not expire until May, has argued that the central bank can afford to be patient about cutting interest rates amid uncertainty about the economic outlook.

Should Fed governors Waller and Bowman both lodge dissenting votes against a committee decision to hold rates steady next month, the tally would show an unusual level of discord.