US Democrat Joe Biden took a huge step Wednesday to capturing the White House, with wins in Michigan and Wisconsin bringing him close to a majority, but President Donald Trump responded with a diatribe alleging mass fraud and demanding a halt to vote counting. In a brief address on national television, flanked by American flags and his Vice Presidential pick Kamala Harris, Mr Biden said he wasn't yet declaring victory, but said that "when the count is finished, we believe we will be the winners." By flipping the northern battlegrounds of Michigan and Wisconsin, Mr Biden reached 264 electoral votes against 214 so far for Mr Trump. By adding the six of Nevada, where he is narrowly ahead, he would hit the magic number of 270 needed to win the White House.