Fox News host Tucker Carlson said Wednesday that when he first learned that the National Security Agency was allegedly monitoring his communications, the news "scared" him.

Carlson, who hosts the No. 1 cable TV news show with an average of more than 3 million viewers in July, made a bold accusation against the Biden administration in late June when he claimed the NSA was "monitoring our electronic communications" and "planning to leak them in an attempt to take this show off the air."

His claims sparked a media firestorm and prompted a rare response from the agency denying his allegations and stating that Carlson "has never been an intelligence target." Shortly after Carlson made the allegations, Axios reported that the cable TV host was communicating with U.S.-based Kremlin intermediaries to set up an interview with Russian President Vladimir Putin, and that the government had learned of his outreach.

In an interview with BlazeTV host Glenn Beck on Wednesday, Carlson described the moment he says he learned that the NSA was monitoring his communications.

"I was in Washington for a funeral. I moved out of Washington after 35 years, I didn't have much choice. And I was back. I ran into a very old, very close friend of mine who said, 'let's get together, and talk about something.' Who said, in person, 'you're planning this trip to Russia,'" Carlson said.

"And I said, well, I haven't told anyone that. So I don't know how you would know. Because — and then this person told me, that the NSA had been reading my electronic communications. My texts and emails. And had unmasked me. And was going to spread this to news organizations, to suggest that I was somehow a disloyal American."

"And it actually scared me," Carlson told Beck. "I'm not normally rattled by stuff. But that's so over the top."

After being told the NSA had allegedly looked at his emails, Carlson said he sought the advice of an unnamed U.S. senator, who suggested that he go public with the allegations "as a self-defense move."

"I felt like kind of a lunatic," Carlson admitted. "You don't want to go on TV — would you want to go on the air and say, they're spying on me? No. You sound like a nutcase. But I didn't feel like I had a choice."

The NSA denied the allegation that Carlson was an intelligence target or that anyone at the agency sought to have his show taken off the air. But critics pointed out that the careful wording of the NSA's public statement did not rule out that Carlson's communications had been incidentally collected or that he had been unmasked by someone working for the government.

The NSA's internal watchdog announced Tuesday that it would open an investigation into Carlson's allegations. Inspector General Robert Storch will examine the agency's "compliance with applicable legal authorities" and its policies on collecting and sharing information. Storch will also examine whether the agency's actions were based on "improper considerations."

Sen. Marco Rubio (R-Fla.), one of the critics of the agency's public denial of Carlson's allegations, welcomed the review as "an important step toward ensuring public confidence. It is important that this review is as transparent as possible so it doesn't fuel further public suspicion and distrust."

But Democratic Rep. Jim Himes of Connecticut, who serves on the House Intelligence Committee, told the Associated Press that Carlson's allegations were the "latest right-wing attempt to damage our security services."

"People like Tucker Carlson can't help themselves," Himes said. "They're badly hurting our intelligence community with outright lies."

Speaking with Beck, Carlson said that his critics are angry with him because he has opinions that dissent from the government-approved narratives.

"You should have the expectation, if you live in America, you criticize the regime, then you they read your email," Carlson said. "So, I thought that was illegal, and un-American. And an assault on civil liberties. But I learned from the Daily Beast, that actually if you complain about it, then you hate America. So just shut up and accept it. You have no privacy. The War on Terror has been turned against American citizens. But you deserve it, because you're a white supremacist. That's what I've been told."

Carlson said that the idea that the law enforcement and national security power of the federal government could be turned against American citizens was a "nightmare scenario" that all Americans should be concerned about.

"You can't turn the awesome law enforcement, and intel-gathering powers of the federal government, against American citizens, on a wholesale basis," Carlson said. "Like, that's the nightmare scenario. We have a lot of laws in place designed to prevent it. Now, it's happening. And it's just bewildering to me, that nobody says anything about it. This is totally cool. This is the way it works. It's not cool. It's not the way it works. If you care about democracy, you're opposed to this, with everything that you have."