U.S. Defense Secretary Chuck Hagel toured the U.S. Navy's new small combat ship, the USS Freedom, the first of a new class of littoral warships recently deployed to Asia to partner with allies in the region.

His visit to the ship on Sunday comes amid nagging questions about the cost and viability of the roughly $34 billion program and whether the Pentagon's plan to buy as many as 52 of the vessels should be chopped by as much as half because of budget constraints.

Docked at Changi Naval Base, the Freedom has been participating in naval exercises with countries in the region, and going through regular maintenance and logistical checks as part of an effort to work through any problems in its maiden mission.

Hagel is the first Pentagon chief to step aboard a littoral combat ship that has deployed, and this was his first visit to any ship as secretary. Former Defense Secretary Robert Gates toured one of the vessels when it was in development at Naval Station Mayport in Florida.

On board the warship, Hagel met with crew members, starting on the deck, where a Black Hawk helicopter stood ready to go, and moving to the bridge and then the compact operations center, with its array of computer stations and displays. He also watched as sailors in a rigid hull inflatable boat demonstrated a launch and landing, easily sliding up into the docking area then returning out in to the Singapore Strait.

The USS Freedom, with its crew of about 90 sailors, arrived in Singapore on April 18, for the first ever overseas deployment of an LCS.

Swift and agile, the smaller ships are designed to operate in littoral waters, which are more shallow and close to shore. Dwarfed by the Navy's larger aircraft carriers and destroyers, the LCS ships give the U.S. the ability to work better with navies from Asian nations — such as Singapore, Malaysia, Brunei and Thailand — that use smaller vessels to patrol the seas or battle piracy. The U.S. Navy's larger ships are often too big to pull into some ports in the region.

With a maximum speed of more than 40 knots — compared to the Navy's larger destroyers and cruisers which travel at about 30 knots — the littoral combat ships are about the size of a Coast Guard cutter. The USS Freedom is a bit longer that a football field.

The ship development program, however, has been fraught with cost hikes, design and construction problems and worries that plans to make two versions of the ship are pricey and may not be necessary.

But Lt. Cmdr. Clay Doss told reporters traveling with Hagel that recent maintenance issues are part of the process any vessel goes through when programs are beginning. It's not unusual, he said, for a ship to experience growing pains that have to be worked out during its first deployment.

Doss said the Freedom is scheduled to leave Singapore in December and the second LCS will arrive in August 2014. In mid-2015 the navy expects to have two of the ships in Singapore and the region at the same time.

Hagel is in Singapore to attend the Shangri-La Dialogue security conference as part of a weeklong trip that will also take him to Brussels for a meeting of NATO defense ministers.

According to a Congressional Research Service report issued about a week ago on the program, the Navy plans to buy 52 ships. So far, the U.S. has bought 12, but plans to buy four this year have been complicated by the automatic budget cuts, known at the sequester. The proposed 2014 budget requests about $1.8 billion for four more.

CRS said there are "concerns over the ships' ability to withstand battle damage, and concerns over whether the ships are sufficiently armed and will be able to perform their stated missions effectively."

The report concluded, however, that the LCS is still the most economical way to meet the mission needs of the Navy. And it said that some of the design and construction issues have been resolved during the normal course of development.

The Navy is buying two versions of the ship, the Freedom and the Independence, and they are designed to be able to be able to switch out various packages of equipment in order to carry out particular missions, such as surface and anti-submarine warfare and mine countermeasures.

The Freedom version is being built by Lockheed Martin with Marinette Marine in Marinette, Wis., and the larger Independence version is being built by General Dynamics Austal USA in Mobile, Ala.