Former President Donald Trump vowed to take action against one of President Joe Biden’s former senior advisers, escalating his threats against members of the Biden administration and other political rivals.

Speaking at a campaign event on Monday, Trump said the adviser would be “brought down,” signaling that he intends to target officials who he claims shielded Biden while in office. The former president did not provide evidence of wrongdoing, but his comments fit into a broader pattern of promising retribution against critics and opponents.

Trump’s remarks come as his allies in Congress push for investigations into Biden’s inner circle. House Oversight Committee Chairman James Comer, R-Ky., has requested testimony from Biden’s former physician, Dr. Kevin O’Connor, as well as senior aides including domestic policy adviser Neera Tanden and deputy chief of staff Annie Tomasini. Republicans allege Biden’s health was in decline during his presidency and accuse aides of covering it up.

The latest comments add to a growing list of figures Trump has recently threatened with investigations or removals, including New York Attorney General Letitia James, Federal Reserve Governor Lisa Cook, former national security adviser John Bolton, and former New Jersey Gov. Chris Christie.

Trump’s campaign has increasingly focused on portraying his political rivals as corrupt, while his critics argue that the former president is seeking to weaponize government agencies for personal retribution.