US President Donald Trump cannot oust Federal Reserve governor Lisa Cook from her role, a federal appeals court has ruled.

The 2-1 ruling on Monday is a blow to Trump as it means Cook can now stay in place for the Fed's policy meeting on Tuesday and Wednesday, where it is expected to cut US interest rates.

Trump announced in August that he was firing Cook on the grounds that she had committed mortgage fraud. Cook denied the allegations and said the president had no authority to sack her.

The case has ramifications for the Fed's ability to set interest rates without interference from politicians.

Cook is part of the board responsible for setting interest rates in the US.