The Navy, seeking a greater role as the United States wages wars far inland, is pushing an expensive, experimental destroyer it says will be able to bomb targets well away from shore.

The Navy is trying to improve its ability to conduct fire support — using heavy guns to assist Marines or soldiers ashore, much like land-based artillery does. The frequency of such naval fire support missions have declined during conflicts of the last half-century, and the Navy has turned to expensive cruise missiles instead of guns to hit targets farther inland.

The proposed destroyer, called the DD(X) (search), would fill a gap opened with the removal from service of the last battleships more than a decade ago, Navy officials contend. But the DD(X) has its critics, who say the Navy is betting on technologies that aren't fully developed and argue the ship is too expensive.

The first DD(X) is projected to cost $3.3 billion, but sister ships would be cheaper, the Navy says. Since 2004, however, the Navy's estimated costs per ship have gone up almost 50 percent for ships built after the first of their class, the Congressional Research Service says.

One proposal before Congress would cap the price per ship at $1.7 billion, forcing the Navy to redesign the DD(X) to something smaller and probably less capable.

The Navy also has reduced the number it wants to buy, from between 16 to 24 down to between eight and 12, prompting fears that the military won't give shipyards enough work and force one to close, the congressional researchers reported recently.

One group wants to see the World War II-era battleships USS Iowa (search) and USS Wisconsin make a comeback, arguing their ability to bombard targets inland with their massive 16-inch guns is unmatched in the fleet. The vessels are inactive but could be returned to service with sufficient investment.

But Navy officials say they don't want the battleships returned to active duty, and there are proposals in Congress to turn them into museums.

Current cruisers and destroyers mount only 5-inch guns with a range of about 15 miles. The guns of the Iowa and Wisconsin can hit targets 30 miles distant with unguided shells carrying 1,900 pounds of high explosives.

The Navy says the guns of the DD(X) will far exceed the capabilities of those on the battleships and the current fleet.

The ship would carry two 155-millimeter guns that fire rocket-propelled rounds. Current test versions of the gun have hit targets 68 miles away. The Navy hopes to reach 96 miles. Navy officials also talk about an electromagnetic rail gun, possibly available by 2020, that can hit targets 350 miles away.

Where the battleships fire unguided shells and destroy targets though massed firepower, rounds from the guns of the DD(X) will be guided by satellite positioning data, like many modern aircraft bombs and missiles, and be far more precise.

The first DD(X) isn't expected to join the fleet until 2013 or so, presuming it continues to receive funding. The Navy also is working on a rocket-propelled shell for its current warships, but that is unlikely to be ready until 2010.

The Navy makes other big promises regarding the DD(X): It will be stealthy and as difficult to detect as an attack submarine; it will have a radar able to pick out targets from along crowded coastlines; it will be heavily automated and need only a small crew.

The ship will also carry at least one helicopter, unpiloted drones, small guns to fight off attacks by small boats, and surface-to-surface and surface-to-air missiles.

Many of those who are pushing the return of the battleships as an alternative to DD(X) are members of the United States Naval Fire Support Association (search), a group of retired military and security officials, who say the absence of battleships exposes ground troops to significant risks.

"The highly effective and versatile battleships are an incredible bargain and should be readied for rapid reactivation, instead of being turned into museums," William L. Stearman, a Navy veteran and the group's executive director, wrote in an e-mail. "Our constantly dwindling fleet could use their massive infusion of firepower and their commanding presence, so effective as an awesome, massive visible show of force where we want to get people's attention and respect."

But Rear Adm. Mark J. Edwards, the Navy's surface warfare chief, says the Navy doesn't want the battleships back for several reasons, most notably the 1,300 to 1,500 crew who are required to operate each one. Plans for the DD(X) call for a crew of 150 or fewer, making the ship far less expensive to operate.

Navy officials also prefer the precision and range of the new destroyer's guns over the raw destructive power of the battleship's.