ABOARD USS INDEPENDENCE (AP) — Operating costs for the U.S. Navy’s newest ships will decline and “become more normal” over time, Navy Secretary Ray Mabus said Thursday.

The Navy designed littoral combat ships to have smaller crews and lower costs than other vessels, but a Government Accountability Office report earlier this month said they each cost about $79 million to operate annually. That’s more than the $54 million it costs to operate a frigate, which are larger and have more sailors on board.