"This confirms all of my suspicions about unjustified, politically motivated government surveillance", Page told The Washington Post Tuesday.
"There had been prior reports, but I was so happy to hear that further confirmation is now being revealed".
In February, Page told PBS that he was a "junior member of the [Trump] campaign's foreign policy advisory group".
The Washington Post also cited the infamous "golden showers" dossier compiled by British spy Christopher Steele, which Page dismissed as "the dodgy dossier".
Though FISA warrants are hard to obtain and numerous judges on the court are Republican appointees, Page went even further, comparing his situation to the FBI's surveillance of Martin Luther King Jr.
The FBI obtained a FISA warrant last summer to monitor the communications of Carter Page, who was an early foreign-policy adviser to Donald Trump's presidential campaign, The Washington Post reported on Tuesday. But information obtained through a FISA warrant could be used in later prosecution. Many investigations like this do not result in any criminal charges.
Officials declined to mention any names or disclose their identity because they were not authorized to discuss details of any probe involving counterintelligence investigations. He had lived in Moscow for several years and worked in the Moscow office of Merrill Lynch and was a guy who was known in Moscow - and we found Merrill Lynch employees with whom he had worked at the time all expressed surprise, I must tell you, that Carter Page would have risen to the position of being a presidential campaign adviser.
The surveillance court requires a detailed and weighty application in order to issue surveillance orders.More news: Chelsea defeat keeps EPL title race open
The government's application for the surveillance order targeting Page included a lengthy declaration that laid out investigators' basis for believing that Page was an agent of the Russian Government and knowingly engaged in clandestine intelligence activities on behalf of Moscow, officials said.
Podobnyy, one of three men charged in connection with a Cold War-style Russian spy ring, had attempted to recruit oil industry consultant Page, later named as a foreign policy adviser to Donald Trump's presidential campaign, as an intelligence source in 2013. When Tapper asked if Sam Clovis, another former Trump campaign official, was the one to bring him on, Page said, "no comment". Page's sketchy associates and shadowy business dealings were enough to lead USA investigators to look deeper.
Asked when he first learned that he was the target of a FISA warrant, Page referred to an article published by the website Heat Street last fall. The official noted that despite the scrutiny and surveillance the fact that there is still no hard evidence of collusion is significant.
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Sessions, while working with the Trump campaign, had met with the Russian ambassador, Sergey I. Kislyak.
The White House, the Federal Bureau of Investigation and the U.S. Department of Justice have all declined to comment on The Washington Post's report.
The FBI, as well as the House and Senate Intelligence Committees, are investigating whether Russian Federation meddled in the US election past year and whether anyone within the Trump campaign coordinating with them in doing so. Podobnyy was secretly recorded commenting on Page's "enthusiasm" and saying he planned to use Page to acquire documents.