Sadiq Khan has congratulated Hillary Clinton for making history by becoming the first woman presumed to lead a major political party into a Presidential election.
Clinton, who has been battling against Bernie Sanders for the Democratic Party nomination, was congratulated by Khan in a post on Twitter on Wednesday.
The Labour mayor hailed Clinton as a "glass ceiling smasher", praising her historic victory with the feminist hashtag #ImWithHer.
A proud feminist, Khan also quoted Clinton, who said at a celebratory rally:
This campaign is about making sure there are no ceilings, no limits, on any of us
Re-posting the message, Khan added his congratulations.
Khan himself was congratulated by Clinton herself back in May, hours after his election as Mayor of London.
Clinton applauded the former Labour MP for being the son of a Pakistani bus driver, champion of workers' and human rights.
She managed to beat prime minister David Cameron to publicly congratulating Khan by almost six days.