Trump continues his crusade against the Federal Reserve and fires Governor Lisa Cook after blaming her for alleged fraud.

US President Donald Trump on Monday fired Lisa Cook , a Federal Reserve governor who the government has decided to investigate for possible mortgage fraud, according to a letter he posted on his Truth Social network.

In the letter to Cook, which bears White House letterhead, the president invokes Article II of the Constitution and the Federal Reserve Act of 1913 and states: "You are hereby removed from your position on the Board of Governors of the Federal Reserve effective immediately."

The president, who called for Cook's resignation last week, arguing that "he's done something wrong," cited Federal Housing Finance Agency Director Bill Pulte's recommendation for a criminal investigation to U.S. Attorney General Pam Bondi .

"As set forth in the criminal recommendation (...), there is reasonable grounds to believe that you may have made false statements regarding one or more mortgage agreements," Trump writes, arguing that Cook signed two mortgages for a "primary residence" in two different states within two weeks.

A U.S. president can remove a member of the Fed's Board of Governors, but only for just cause, which usually involves malpractice or criminal behavior, but never a disagreement over monetary policy.

However, Trump's arguments regarding this case for dismissing the Fed governor under current laws are likely to trigger a legal battle.

In his letter, Trump stated that the United States "must have full confidence in the honesty of the members charged with setting policy and overseeing the Federal Reserve" and argued that Cook's alleged "negligence" calls into question his regulatory "competence."

Cook, in a subsequent statement to the media, said Trump "has no authority" to fire her because "there is no cause under the law," assured her that she will continue working and hired attorney Abbe Lowell, who in turn denounced the decision as a "firing by tweet" and anticipated a lawsuit.

The crackdown on Cook, who was nominated for the post by former Democratic President Joe Biden , adds to the pressure the Trump administration is putting on the Fed and its chairman, Jerome Powell, calling on him to lower rates.