Former U.S. President Barack Obama will campaign for vice president and Democratic presidential candidate Kamala Harris in the month leading up to the November 5 U.S. election, the Washington Post reported on Friday.

Obama will kick off his efforts with a trip to Pittsburgh on Thursday, the Washington Post said, citing a senior campaign official who spoke on condition of anonymity. Obama and his wife Michelle endorsed Kamala Harris' bid for president in July.

Obama urged Americans to back Harris at the Democratic National Convention that took place at Chicago in August. "America is ready for a new chapter. America is ready for a better story. We are ready for a President Kamala Harris," he said at the time.

Harris, a Democrat, faces Republican candidate Donald Trump in what polls show to be a tight presidential race.