The refinery in Fao will have the capacity to produce 300,000 barrels per day and will include a petrochemical plant, he told Reuters, saying the agreement was signed on Saturday in Iraq.
The Fao refinery south of Basra is one of several Iraq plans as it seeks by Iraq to become self-sufficient in oil products.
Iraq is OPEC's second-largest oil producer, after Saudi Arabia. Its refining capacity was curbed when Islamic State overran its largest oil processing plant in Baiji, north of Baghdad, in 2014.
Iraqi forces recaptured Baiji in 2015 but it sustained heavy damage in the fighting. The country now relies on the Doura refinery in Baghdad and the Shuaiba plant in the Basra region.