ABOARD USS INDEPENDENCE » 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.

As more of the ships enter the fleet and are used, the costs will be "well within acceptable limits" Mabus told The Associated Press during a visit to the USS Independence, the second littoral combat ship to be commissioned, while it participated in exercises off Hawaii.

"I think as we get into the operations, you’re going to see them become more normal," Mabus said of the costs.

Mabus said he’s reviewed GAO reports on new classes of Navy ships going back to the 1960s. They echo the latest reports on the littoral combat ship, he said.

"They are always concerned about the operating costs. They’re always concerned about the operational ability of the ship. They’re always concerned about whether the ship can do anything or how it’s going to fit into the fleet," he said.

New vessels are more expensive to operate and start off with more difficulties, in part, because ships have to be tested as they’re being built. Unlike aircraft, you can’t build a few and test them, and then build more, Mabus said.

"Ships are too expensive to do that," Mabus said.

Littoral combat ships are designed to operate in relatively shallow water. They Navy aims to use them to find and disable mines, locate quiet diesel submarines and face down fast surface craft.

The Navy plans to deploy littoral combat ships to Singapore on a rotational basis. The first to go on this mission, the USS Freedom, is a different version of the ship. It deployed to Singapore last year.

Defense Secretary Chuck Hagel said in February that the Navy would build 32 of the vessels instead of the 52 initially planned. If all of the initially planned vessels were built, the littoral combat ships would account for one-sixth of a 300-ship fleet.

Hagel said the Navy also needed to examine whether the ships have the firepower to survive against more advanced military adversaries and new technologies, especially in Asia and the Pacific.

The next littoral combat ship to deploy to Singapore will be the USS Fort Worth, which is the same type of vessel as the Freedom. It’s expected to deploy later this year for 16 months, after it completes operational tests.