US election hinges on Wisconsin, Michigan and Pennsylvania

Wisconsin, Michigan and Pennsylvania could, once more, decide who wins the White House (AP/Michael Perez)

US President Donald Trump and his Democratic challenger Joe Biden are focused on the three northern industrial states of Wisconsin, Michigan and Pennsylvania that could determine who wins the White House.

Four years after Mr Trump became the first Republican in a generation to capture that trio of states, they are again positioned to influence the direction of the presidential election.