The US extracted a high-level spy from inside Russia in 2017, reports BBC.
Citing "multiple Trump administration officials with direct knowledge" of the operation, CNN reported that US intelligence feared the source's cover could be blown by US officials.
The decision was made soon after a meeting in which President Trump unexpectedly shared classified US intelligence with Russian officials.
According to the New York Times, the source was instrumental in the conclusion by US intelligence agencies in 2016 that Mr Putin had personally orchestrated Russia's interference in the US presidential election.
Reports said the mole was the highest-level US source inside Russia.
Reporting by CNN and the New York Times said the source was outside the inner circle of Russian leader President Putin but had regular access to Mr Putin and was even able to photograph documents on the leader's desk.