London CNN  — 

The mayor of London, Sadiq Khan, compared Donald Trump to a young child after the US President called him a “stone-cold loser.”

Khan told CNN that he was “not offended in the slightest” by the remarks, delivered as Trump began his state visit to the UK on Monday, but added that the US was expected to behave more like a role model.

“This is the sort of behavior I would expect from an 11-year-old,” Khan said. “But it’s for him to decide how he behaves. It’s not for me to respond in a like manner. I think it’s beneath me to do childish tweets and name-calling.”

Trump is in London for a three day state visit, a trip marked by both pageantry and protests.

The president received a royal welcome from Queen Elizabeth on Monday, completed with a guard of honor march, gun salutes and opulent white- tie state banquet at Buckingham Palace.

But the visit has also attracted anti-Trump protests. As Khan spoke to CNN at City Hall in London, a large inflatable caricature of the US President as a diaper-wearing baby was inflated outside the UK Parliament.

Khan said people in London had the right to protest, as long as it’s done peacefully. “They’ll be articulating the concerns we have about the values we both hold dear,” Khan said.

Asked whether the UK should be pragmatic in its approach to Trump, given its desire for a post-Brexit trade deal, Khan warned against false hopes. “His mood changes from hour to hour,” Khan said. “He can be upset by an article in a Sunday newspaper to the effect that he resorts to name-calling.”