The US extracted "one of its top secret sources within the Russian government" in 2017, it was reported on Monday, partly because of concerns that mishandling of classified intelligence by Donald Trump and his government could compromise the security of the source.
CNN quoted "several directly knowledgeable Trump administration officials" on the subject and said that "a person directly involved in the discussions" said the move was taken because Trump and his employees were not fully trustworthy.
Describing a "culmination of months of growing fear in the intelligence community," CNN said the decision to extract was taken shortly after a now infamous 2017 Oval Office meeting in May, where Trump, who recently fired the FBI Director James Comey discussed highly sensitive information about Isis in Syria with Russian Foreign Minister Sergei Lavrov and then US Ambassador Sergey Kislyak.
The report also said US officials were alarmed by Trump's private meeting with Russian President Vladimir Putin in Hamburg in July of that year.
CNN quoted "a source aware of the intelligence community's response" to the Trump and Putin meeting, saying: "The authorities again expressed concern that the president may have improperly discussed classified intelligence with Russia."
He also said that Trump and "a small number of senior officials" were "informed before extraction."
The report added: "The details of the extraction itself remain secret and the whereabouts of the asset today is unknown by CNN."
The 2010 leak of US diplomatic telegrams has revealed how successive US administrations have been striving to find high-level assets within the Russian government with genuine knowledge of key decisions and actors.
Overall, American diplomats relied on a public network of Russian scholars and journalists to understand Kremlin affairs. The Kremlin - largely formed by former KGB officers - is paranoid about Western, especially American, spies.
The penalty for cooperating with Western intelligence services was revealed in a series of extraterritorial killings, including Alexander Litvinenko's murder of 2006 polonium in London, and 2018's novichok attack on former GRU military intelligence officer Sergei Skripal.
In 2017, Russia arrested two senior cyber security officials in the FSB security services and accused them of traitorous ties with the CIA. Russian media reported that one of the men had left a meeting at the FSB with a bag over his head.
The last known US intelligence resource to be exiled from Russia was Alexander Poteyev, deputy director of the "illegal" US-operating spy program run by Russia's foreign intelligence service. He escaped from Russia on 2010, shortly before the FBI arrested 10 Russian agents in the US, whose identities he is believed to have given to the Americans. By default in Russia, it was reported that he fled the country via Belarus with a passport belonging to a Russian citizen who had already applied for an American visa. He now lives hidden in the USA.
On Monday, John Sipher, a former member of the CIA Senior Intelligence Service, tweeted: “Recruiting a source with important access is extremely difficult. A source in a key position can happen once a generation, if ever. Keeping it safe is a daunting job. It is very important to lose this type of font. "
The mystery of Trump's relationship with - and publicly expressed consideration for - Vladimir Putin, meanwhile, fuels continuing speculation.
Earlier this year, special attorney Robert Mueller completed a nearly two-year investigation into the matter. Mueller did not establish a conspiracy between Trump and Moscow aides, but established extensive contacts between Trump and Russia and several cases of possible obstruction of justice by the president.
On Monday, White House press secretary Stephanie Grisham told CNN that her reports were "not only incorrect but also potentially life-threatening."
CIA Director of Public Affairs Brittany Bramell said her “narrative that the Central Intelligence Agency makes life or death decisions based on something other than objective analysis and sound collection is simply false.
"Misguided speculation that the handling of our nation's most sensitive intelligence president - to which he has access every day - has led to an alleged exfiltration operation is inaccurate."
Soon after the CNN report was released, the president attacked the network on Twitter.
Trump did not immediately mention the report, commenting on the network's corporate fortunes and adding, "But most importantly, CNN is bad for the US."