President Donald Trump has threatened to take "appropriate action" against Federal Reserve Governor Lisa Cook, escalating tensions between the White House and the central bank just hours after the US Supreme Court blocked his attempt to remove her from office.

In a post on Truth Social, the president did not specify the nature of the threatened measures, stating only that he intends to ensure that someone who has "committed violations" does not remain in a position of power.

The vague language has sparked immediate speculation among market observers about whether the administration might pursue legislative changes, regulatory pressure, or further legal challenges to undermine Cook’s authority.

The threat follows a significant legal setback for the White House earlier in the day.

The Supreme Court ruled that Trump lacks the constitutional authority to unilaterally dismiss a Federal Reserve governor, delivering a clear victory for central bank independence.

The court’s majority opinion reinforced the statutory protections designed to insulate monetary policy from direct political interference.