Chief Executive Seiji Izumisawa confirmed delays with a new fuselage for the jet.

"Given where we are in the process today, which is we're revisiting the schedule to consider what the schedule will be, everything becomes hypothetical," he said an interview with Reuters, referring to the mid-2020 delivery target to customer All Nippon Airways.

"We may, we may not, but I simply cannot commit to it," he said.

(Reporting by Alwyn Scott; editing by Tim Hepher and Bernadette Baum)