Donald Trump has expressed mock surprise after Vladimir Putin appeared to endorse his rival Kamala Harris for the US Presidency speaking at a rally in the key swing state of Wisconsin Mr Trump told supporters he didn't believe Mr Putin was serious and insisted he was the toughest candidate in his approach to Moscow Russia would have never happened if I were president attacking Ukraine would have never happened I knew Putin I knew him well and you know he endorsed I don't know if you saw the other day he endorsed Camala he endorsed Kamala I was very uh offended by that I wonder why he endorsed Cala now he's a chess player I Endor Cala should I be Congressman should I be uh upset about that no huh was it done with a smile Ron was it done with a smile I think it was done maybe with a smile I don't know who the hell knows nobody