US President Donald Trump has revoked the security clearance of former CIA director John Brennan, White House press secretary Sarah Huckabee Sanders announced, citing "the risk posed by his erratic conduct and behaviour."
Brennan has been a leading critic of Trump.
Trump is also reviewing security clearances of other former officials including former FBI director James Comey, Sanders said during a regular White House news briefing.
"First, at this point in my Administration, any benefits that senior officials might glean from consultations with Mr Brennan are now outweighed by the risk posed by his erratic conduct and behaviour," Trump said in a statement read by Sanders.
"Second, that conduct and behaviour has tested and far exceeded the limits of any professional courtesy that may have been due to him," Trump said. "Mr Brennan has a history that calls into question his objectivity and credibility."
Last month, Sanders said Trump was "looking to take away" the clearances of Brennan and half a dozen other former senior national security and intelligence officials who served in the administrations of George W. Bush or Barack Obama.
Those officials included former CIA director Michael Hayden, former national security adviser Susan Rice, former director of national intelligence James Clapper and former FBI deputy director Andrew McCabe.
Today, Sanders expanded that list to include former acting attorney-general Sally Yates, former FBI lawyer Lisa Page, former FBI agent Peter Strzok and former Justice Department official Bruce Ohr.
The announcement that Brennan's clearance had been revoked triggered an outcry from critics who argued that the move was aimed at silencing critics of the President.
In an appearance on CNN shortly after Sanders's appearance in the White House briefing room, Clapper described the move as "unprecedented" and an "infringement on our rights of speech," noting that all of the former officials on Trump's list have been outspoken in their criticism of Trump at one point or another.
Clapper maintained that the move would not affect his own decision on whether to speak out against the president.
"If they're saying that the only way I can speak is to be in an adulation mode of this president, I'm sorry, I don't think I can sign up for that," he said.
Ben Rhodes, a deputy national security adviser during the Obama Administration, echoed Clapper's criticism in an appearance on MSNBC in which he blasted the move as "authoritarianism in its purest form."
Last month, House Speaker Paul Ryan, (R), had downplayed Trump's threat to revoke the officials' security clearances, telling reporters at the Capitol, "I think he's trolling people, honestly."