WASHINGTON--U.S. President Donald Trump suggested challenging licenses for NBC and other broadcast news networks following reports by NBC News that his secretary of state had called him a "moron" after a discussion of the U.S. nuclear arsenal.


"With all of the Fake News coming out of NBC and the Networks, at what point is it appropriate to challenge their License? Bad for country!" Trump, a Republican, wrote in a post on Twitter on Wednesday.
Trump and his supporters have repeatedly used the term "fake news" to cast doubt on media reports critical of his administration, often without providing any evidence to support their case that the reports were untrue. Trump kept up his criticism of the media in an appearance with Canadian Prime Minister Justin Trudeau, saying: "It is frankly disgusting the press is able to write whatever it wants to write."
In a tweet late on Wednesday, Trump said: "Network news has become so partisan, distorted and fake that licenses must be challenged and, if appropriate, revoked. Not fair to public!"
Any move to challenge media companies' licenses, however, would likely face significant hurdles. The Federal Communications Commission, an independent federal agency, does not license broadcast networks, but issues them to individual broadcast stations that are renewed on a staggered basis for eight-year periods.
Comcast Corp, which owns NBC Universal, also owns 11 broadcast stations, including outlets in New York, Washington, Los Angeles, San Francisco, Boston, Dallas and Chicago. A Comcast spokeswoman referred questions to NBC, which did not immediately respond.
ABC, owned by Walt Disney Co, declined to comment. Shares in media companies fell, potentially reflecting concerns the war of words could worsen. Comcast was down 0.8 percent, while Disney shed 1.4 percent. CBS Corp fell 1.2 percent and Twenty-First Century Fox slid 2.8 percent.
Recon Analytics analyst Roger Entner called the market response a "short-term irrational knee-jerk reaction" and said Trump faced essentially insurmountable hurdles to getting licenses pulled. A spokesman for FCC Chairman Ajit Pai did not immediately comment.
Gordon Smith, the chief executive of the National Association of Broadcasters, defended the media's free speech rights. "It is contrary to this fundamental right for any government official to threaten the revocation of an FCC license simply because of a disagreement with the reporting of a journalist," Smith said in a statement.
ABC, owned by Walt Disney Co, declined to comment.