Thomson Reuters
Ajit Pai, Chairman of the Federal Communications Commission, testifies before a Senate Appropriations Financial Services and General Government Subcommittee on Capitol Hill in Washington
During a panel at George Washington University on Tuesday, Pai said the agency does not have the legal authority to revoke a broadcaster's license over speech with which the president disagrees.
"The FCC does not have the authority to revoke a license of a broadcast station based on the content," Pai said. "The FCC under my leadership will stand for the First Amendment."
Most observers and analysts said Trump's threat to NBC News was empty.
Television licenses are granted to individual stations affiliated with national networks, and are rarely stripped by the federal government. When they are, it is usually based on complaints by local residents when a station has violated the FCC's rules or committed a felony.
Pai previously lamented the number of complaints the FCC received about taking away licenses from cable broadcasters.
"On Twitter, for example, seemingly on a daily basis, people regularly demand that the FCC yank the licenses of MSNBC or Fox News or CNN or any other number of news outlets because they disagree with the opinions they may have seen on one of those cable news networks," Pai said.
"Setting aside the fact that the FCC doesn't license those cable channels - kind of an important technicality when one is thinking about these things - these demands are fundamentally at odds with America's cultural and legal traditions," he added.