I suppose it depends on what you thought to start with. Personally I'd side with Sadiq Khan on this -- why should Trump make an exception for him specifically, and how much worth has that when, say, Khan's parents wouldn't be treated to the same exemption?
Trump's position is from the same school of thought as the "some of my best friends are ____" approach -- although, that said, I thought it was interesting to see him so full of praise for Sadiq Khan's achievement, rather than joining on the doom-mongering response that we've had so much of, particularly on AB, in the last few days.