AsianFin -- U.S. President Donald Trump on Wednesday called for the resignation of Federal Reserve Governor Lisa Cook following claims from one of his allies that she engaged in mortgage fraud.

The controversy stems from a letter dated August 15, in which Federal Housing Finance Agency Director Bill Pulte urged the Justice Department to investigate two mortgages taken out in recent years by Cook.

Trump amplified the allegations on his social media platform, writing, “Cook must resign, now!!!”

Cook, however, rejected the calls to step down, asserting that she would not be “bullied” out of her position.

“I learned from the media that FHFA Director William Pulte posted on social media that he was making a criminal referral based on a mortgage application from four years ago, before I joined the Federal Reserve,” Cook said in a statement.