Trump fires off insults at London's mayor as Air Force One approaches Britain: 'Stone cold loser!'

President Donald Trump bashed London's mayor as Air Force One approached the city for a state visit.

The president insulted the city's Muslim mayor, Sadiq Khan, in a pair of tweets early Monday before arriving at London’s Stansted Airport.

"@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," Trump tweeted. "He is a stone cold loser who should focus on crime in London, not me."

"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 added. "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!"

Khan’s spokesman responded by saying “childish insults” should be “beneath the president of the United States."