WASHINGTON — Obama administration officials struggled Wednesday to defend their initial statements that the Boeing 787 Dreamliner is safe while promising a transparent probe of mishaps involving the aircraft’s batteries.

Transportation Secretary Ray LaHood stood by his Jan. 11 assertion that the 787, Boeing’s newest and most technologically advanced airliner, was safe. At that time, LaHood and the head of the Federal Aviation Administration, Michael Huerta, declared the plane fit to fly despite a battery fire in one plane.