The Vietnam Navy is negotiating with Damen Schelde Naval Shipbuilding (DSNS) for the procurement of four Sigma-class corvettes, a US defence official has said.
The submarine procurement plan is a part of Vietnam's surface and submarine fleet modernisation programme in response to China's growing military strength.
The plan also includes the construction of two of the four ships in Vietnam under a technology transfer agreement.
Sigma-class corvettes are built to sizes ranging from 50-150m in length and 9-15m width, and are capable of performing the whole spectrum of offshore patrol vessel (OPV) operations.
The vessels are currently used by the Indonesian and Moroccan Navies.