The 200,000-barrel-per-day refinery will process 7.96 million tonnes of crude oil this year, the ministry said in a statement.

This will be the first major maintenance at the refinery, which started commercial production in May, 2018. The refinery supplies more than a third of Vietnam's needs for refined fuels.

Nghi Son Refinery and Petrochemical suffered a leak at its residual fluid catalytic cracking (RFCC), which had been shut down since late last month.

The ministry said the unit will be restarted on Jan. 15 at the latest. The closure of the unit causes a 20%-25% fall in the refinery's total output.

Nghi Son refinery is 35.1% owned by Japan's Idemitsu Kosan Co, 35.1% by Kuwait Petroleum, 25.1% by Vietnam's state oil firm PetroVietnam and 4.7% by Mitsui Chemicals Inc.

Vietnam's other refinery, the 130,000-barrel-per-day Binh Son, will also be shut down from June 22 through to August 11 for maintenance.

(Reporting by Khanh Vu; Editing by Ed Davies)