'I'm OK,' Biden insists on return to campaign trail

US President Joe Biden returned to the campaign trail on Friday in Michigan, seeking to reassure voters and Democrats about his ability to serve, following calls for him to step down after a major news conference. "We've got to finish the job. And I promise you I am OK," the 81-year-old president told supporters at a diner in Northville, Michigan, a crucial state he needs to win in the upcoming election against Donald Trump.