"There is no estimated date of completion" to the repair works, it added.
According to the initial indications, the gear damage "appears to be caused by a failure to follow established procedures during maintenance." The incident took place on January 12 when the ship was in Singapore.
It will remain in Singapore while it undergoes "a series of inspections to determine the extent of necessary repairs," Lieutenant Commander Matt Knight, a spokesman for the Navy’s Pacific Fleet, was quoted as saying by Bloomberg.
The USS Fort Worth is on a 16-month deployment to Asia, as part of Obama administration’s strategy of rebalance in Asia. The Navy plans to have four littoral ships permanently deployed in Singapore.
The incident is the second in little more than a month involving vessels which cost on average about $440 million each, according to the Congressional Research Service.
On December 11, The US Navy combat ship Milwaukee broke down in the open sea while transiting from Halifax, Canada, to Mayport, Florida, and ultimately its home port of San Diego. The ship sustained a failure in its propulsion plant.
According to the memo, the two incidents were not related.