White House Press Secretary Sarah Sanders made the announcement on Monday, justifying the possible move as a response to the alleged "politicization" of the posts and agencies those officials held and headed in the past, Efe news reported.

"The President is exploring the mechanisms to remove security clearance because they've politicized and, in some cases, monetized their public service and security clearances," said Sanders at a press briefing.

"Making baseless accusations of improper contact with Russia or being influenced by Russia against the President is extremely inappropriate. And the fact that people with security clearances are making these baseless charges provides inappropriate legitimacy to accusations with zero evidence," she said.

Five of the six ex-officials Sanders mentioned worked for former President Barack Obama: Brennan; Comey; Director of National Intelligence James Clapper; National Security Adviser Susan Rice; and Andrew McCabe, who was deputy director of the FBI.

The sixth, Michael Hayden, led the National Security Agency prior to his 2006 appointment by President George Bush to run the CIA.

All of them have criticized Trump's actions or have defended the intelligence agencies against the President's attacks.

Sanders defended the possible move by saying that Trump "doesn't like the fact that people are politicizing agencies and departments that are specifically meant to not be political and not meant to be monetized off of security clearances".

She said that "when you're the person that holds the nation's deepest, most-sacred secrets at your hands, and you go out and you make false accusations against the President of the United States. (Trump) thinks that is something to be very concerned with, and we're exploring what those options are."

Sanders made her announcement after Republican Sen. Rand Paul met with Trump and tweeted that the president should revoke Brennan's security clearance because last week the former CIA chief used the word "treason" to refer to the president's actions during the Helsinki summit with Russian President Vladimir Putin.