President Donald Trump had some important business to attend to as soon as he landed in London Monday morning: Get to the nearest television and tune in to American cable news.

The U.S. leader often slams U.S. media outlets as “fake news.” But those who watch him closely know he often is obsessed with how cable news networks and a handful of major print outlets cover him and his presidency.

Air Force One touched down around 4 a.m. ET at London’s Stansted Airport, where Trump and first lady Melania Trump were greeted by a military honor guard. From there, they took Marine One to Winfield House, home to the U.S. ambassador to that country, in Regent’s Park in the British capital.

And he made clear he had much to do once inside. But it wasn’t dictating a statement to apologize for calling Meghan Markle, the American-born Duchess of Sussex, “nasty” in a conversation with “The Sun,” a British tabloid. (Trump tweeted he never called the former actress that word, but he is on tape doing so.)

[Another ally prepares to fete Trump, but ample disputes remain]

Just under three hours after landing, the president told the world about his biggest gripe with his accommodations and host country.

He wrote in a social media post that “the only problem is that @CNN is the primary source of news available from the U.S.”

Trump could have used the time before departing to Buckingham Palace to prepare for his private lunch with Queen Elizabeth II — which brings a number of etiquette challenges Trump has tripped over before — or his Tuesday one-on-one meeting with outgoing British Prime Minister Theresa May.

But he instead chose to become enraged by CNN’s morning show “New Day.”

“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?” Trump wrote, tagging CNN’s parent company in an open plea to cancel a show that often offers critical thinking about his turbulent presidency and policies.

Just arrived in the United Kingdom. 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?

— Donald J. Trump (@realDonaldTrump) June 3, 2019

But the president wasn’t done. Not even close.

Less than an hour before he and the first lady were scheduled to meet Queen Elizabeth for the first time on what is an official state visit, Trump felt the need to urge Americans to punish AT&T for owning a cable network that covers him critically.

“I believe that if people stoped (sic) 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!” he wrote, saying the network gives people in other countries a “false picture” of the U.S.

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!

— Donald J. Trump (@realDonaldTrump) June 3, 2019

[White House brushes off Grassley, GOP concern over Mexico tariffs]

If his cable news focus was not eyebrow-raising enough, Trump’s arrival did not amount to a diplomatic charm offensive.

As Air Force One descended into London’s airspace, Trump poured lighter fluid on his ongoing feud with London Mayor Sadiq Khan, who last week approved a giant balloon depicting the 44th U.S. commander in chief as an adult baby. Khan has long been a leading Trump critic.

The president accused Khan of doing “a terrible job as Mayor of London,” saying he had been “foolishly ‘nasty’ to the visiting President of the United States.” Unconcerned with offending his hosts, the bare-knuckled approach of the president was evident on the other side of the Atlantic Ocean, calling Khan “a stone cold loser who should focus on crime in London.”

But Trump appeared in a fighting mood after his flight to the UK, comparing Khan to a domestic political foe: New York Mayor Bill de Blasio, whom Trump slammed last month when the Democrat announced his 2020 White House candidacy. Trump chose to engage the New York mayor despite his low national poll numbers and long shot chance at becoming his party’s nominee.

“Kahn reminds me very much of our very dumb and incompetent Mayor of NYC, de Blasio, who has also done a terrible job — only half his height,” he tweeted.

.@SadiqKhan, who by all accounts has done a terrible job as Mayor of London, has been foolishly “nasty” to the visiting President of the United States, by far the most important ally of the United Kingdom. He is a stone cold loser who should focus on crime in London, not me……

— Donald J. Trump (@realDonaldTrump) June 3, 2019

….Kahn reminds me very much of our very dumb and incompetent Mayor of NYC, de Blasio, who has also done a terrible job – only half his height. In any event, I look forward to being a great friend to the United Kingdom, and am looking very much forward to my visit. Landing now!

— Donald J. Trump (@realDonaldTrump) June 3, 2019