US Navy officers in the Pacific fleet say the service's Littoral combat ships may lack the speed, range and electronic warfare capabilities needed to operate in Asian waters, according to a congressional audit.
"Several 7th Fleet officials told us they thought the LCS [Littoral combat ships] in general might be better suited to operations" in the smaller Persian Gulf, the US Government Accountability Office (GAO) said in a 56-page report, labelled "For Official Use Only".
The navy should consider buying fewer of the ships if its limitations prevent effective use in the Pacific, according to the report by GAO, a watchdog agency.
The report follows others that have questioned the cost, mission and survivability in combat of the ship that is designed to operate in shallow coastal waters.
Defence Secretary Chuck Hagel said in a February memo that "considerable reservations" led him to bar negotiations for any more than 32 of the vessels, 20 fewer than called for in the navy's US$34 billion programme. The Littoral combat ship is made in two versions by Lockheed Martin and Austal.
Hagel's doubts may be bolstered by the new audit, with conclusions that were summarised in its title: "Littoral Combat Ship: Additional Testing and Improved Weight Management Needed Prior to Further Investments."
The first two vessels, one from each maker, are overweight, resulting in "not meeting performance requirements" for endurance or sprinting over 40 knots, the report said.
"This situation had led the navy to accept lower than minimum requirements" on the two ships, the report said.
The report was likely to be discussed yesterday at a hearing of the Senate Armed Services Committee's seapower panel.
Lieutenant Caroline Hutcheson, a navy spokeswoman, said in an e-mailed statement that the service was aware the report was coming out.
"We continuously refine and test the LCS programme to learn the full extent of possibilities for these first-of-a-kind ships," she said.