WASHINGTON — President Donald Trump abruptly revoked the security clearance of ex-CIA Director John Brennan on Wednesday, an unprecedented act of retribution against a vocally critical former top US official.

Trump also threatened to yank the clearances of a handful of individuals, including former top intelligence and law enforcement officials, as well as a current member of the Justice Department. All are critics of the president or are people whom Trump appears to believe are against him.

Trump in a statement denounced Brennan's criticism and spoke anxiously of "the risks posed by his erratic conduct and behavior." The president described his own action as fulfilling his "constitutional responsibility to protect the nation's classified information."However, Democratic members of Congress said it smacked of an "enemies list" among fellow Americans and the behavior of leaders in "dictatorships, not democracies."

Brennan, in a phone interview with MSNBC, called the move an "abuse of power by Mr. Trump.""I do believe that Mr. Trump decided to take this action, as he's done with others, to try to intimidate and suppress any criticism of him or his administration," he said, adding that he would not be deterred from speaking out.

Trump's action, critics and nonpartisan experts said, marked an unprecedented politicization of the federal government's security clearance process. It also was a clear escalation in Trump's battle with members of the US intelligence community as the investigation into Russia election meddling and possible collusion and obstruction of justice continues.

And it came in the middle of the president's latest controversy — accusations of racism by former adviser Omarosa Manigault Newman and his bitter reaction to them. Trump's statement, distributed to reporters, was dated July 26, 2018, suggesting it could have been held and then released when needed to change a damaging subject. The White House later released a new version without the date.

Trump, his statement read by his press secretary, accused Brennan of having "leveraged his status as a former high-ranking official with access to highly sensitive information to make a series of unfounded and outrageous allegations, wild outbursts on the internet and television about this administration."