It confirmed that the first vessel was expected to arrive in November.
Secretary of the Ministry of Ports and Aviation Ranjith Silva said there would be a formal ceremony, on August 15 , to mark the the filling of the harbour basin with water.
He confirmed that the first phase of the project would include bunkering, ship repair facilities and other services.
Hambantota is scheduled to become Sri Lanka's second largest port after Colombo.
Construction, which has been led by Chinese companies, began in 2008.
When complete, the port is scheduled to have a 310 metre bunkering berth and a tank farm.
Sri Lankan officials have conceded that bunker demand at Hambantota may be slow, at least while the port is still being developed.
“Initial demand at Hambantota may be limited, especially given lack of storage,” an official with the Sri Lanka Ports Authority (SLPA) said late last year.
Hambantota is on Sri Lanka's south coast, close to international shipping lanes.
The port's bunker terminal, which is scheduled for completion early next year, will have eight storage tanks.
The SPLA, which will operate the port, has said it plans to set up a subsidiary to hire barges to store and supply bunker fuel until onshore tanks are built.