Boeing is sticking with plans to speed up production of its 787 and sees no reason to change the lithium-ion battery design at the center of the troubled plane's problems, its CEO said Wednesday.

Boeing's full-speed-ahead approach comes even as it became clear that airlines were replacing 787 batteries more often than Boeing had expected. A fire and emergency landing earlier this month, both involving the batteries, prompted regulators to ground Boeing's newest and highest-profile plane.

Airlines have been replacing 787 batteries at a rate that's "slightly higher" than Boeing had expected, CEO Jim McNerney said on Wednesday. None of the replacements have been for safety concerns, he said, and noted that replacing batteries in planes is not uncommon.

U.S. aviation officials said they have asked Boeing for a full operating history of the batteries on the 787s.

Boeing is still building 787s even though it has halted deliveries to customers. It still aims to deliver at least 60 of the planes in 2013, and it's on track to speed up production from five per month now to 10 per month by year end, McNerney said.