(Reuters) - Mexico inaugurated one of President Andres Manuel Lopez Obrador's flagship infrastructure projects, a new oil refinery in the southern port of Dos Bocas, though it likely will not be ready to start producing gasoline until 2023.

The Olmeca refinery, owned and operated by state-run oil company Petroleos Mexicanos (Pemex), is running considerably over budget, and Lopez Obrador recently conceded it would end up costing between $11 B-12 B, rather than the $8 B originally estimated.

In April, however, people close to the project told Reuters it could cost at least $14 B.

Lopez Obrador also said it will begin production next year.

The project was inaugurated on Friday even though it is unfinished. Two people familiar with the matter told Reuters it will only be running near capacity in 2025.

The leftist president argues that the refinery, Mexico's first such new facility built in four decades, is needed to wean the country off foreign supplies of motor fuels, mostly imported from U.S. refiners.

The refinery, with a crude processing capacity of 340,000 barrels per day, should be Pemex's largest once it comes online.