President Donald Trump, shortly after touching down in the UK on Monday, complained that the only widely available US news network was CNN.

Trump said CNN was being too negative and told consumers to boycott its parent company, AT&T, as "they would be forced to make big changes at CNN."

Visit Business Insider's homepage for more stories.

President Donald Trump, in a tweet Monday morning, encouraged customers of AT&T to boycott the company to force it to make editorial changes at the CNN news network, which it owns.

The president wrote as he was preparing to meet Queen Elizabeth II at the start of a three-day state visit to the UK.

He said the only US news network he could find to watch after landing was CNN, which he found too negative in its coverage of the US.

"When the World watches @CNN, it gets a false picture of USA," he wrote. He suggested that a boycott could prompt "big changes" in CNN's output.

"Just arrived in the United Kingdom," he tweeted. "The only problem is that @CNN is the primary source of news available from the U.S. After watching it for a short while, I turned it off. All negative & so much Fake News, very bad for U.S. Big ratings drop. Why doesn't owner @ATT do something?"

"I believe that if people stoped using or subscribing to @ATT, they would be forced to make big changes at @CNN, which is dying in the ratings anyway. It is so unfair with such bad, Fake News! Why wouldn't they act. When the World watches @CNN, it gets a false picture of USA. Sad!"

CNN is owned by Time Warner, which AT&T acquired last June.

If the president was hoping to tune in to Fox News, his preferred cable-news channel, in the UK, he would be disappointed.

21st Century Fox in 2017 announced it would stop broadcasting Fox News in the UK because it got such low viewing figures.

Trump has not let up with his Twitter tirades on the state visit, attacking Mayor Sadiq Khan as a "stone cold loser" as Air Force One entered UK airspace on Monday after Khan compared Trump to fascist dictators.