She wrote: "It's high time the media and everyone leave Barron Trump alone and let him have the private childhood he deserves."

Ms Clinton continued: "Dear Matty-Barron is A KID. No child should be talked about in the below manner-in real life or online. And for an adult to do so? For shame."

Melania Trump thanked her, writing: "Thank you @ChelseaClinton - so important to support all of our children in being themselves! #StopChildhoodBullying"