WASHINGTON—General Motors Co (GM) and Ford Motor Co both said on Thursday they will cut more vehicle production due to a semiconductor chip shortage that has roiled the global automotive industry. The White House plans a summit on the chip shortage issue next Monday that is expected to include GM Chief Executive Mary Barra and Ford Chief Executive Jim Farley and top technology firm executives. An auto industry group this week urged the government to help and warned that a global semiconductor shortage could result in 1.28 million fewer vehicles built this year and disrupt production for another six months. President Joe Biden wants at least $50 billion to help boost semiconductor production, but that will not address short-term needs. “This is something that there is a great deal of focus at the highest level across government,” White House spokeswoman Jen Psaki said. General Motors, the largest U.S. automaker, said it …