Nigeria’s President Muhammadu Buhari on Monday commissioned an oil plant billed as Africa’s largest oil refinery, after years of delays and a week before stepping down from office.

Built by Africa’s richest person Aliko Dangote in the commercial hub of Lagos, the refinery should begin operations in June with the first products expected on the market by August though some analysts said it could be later.

Once at full capacity, it will have the ability to process 650,000 barrels a day, according to the company.

Buhari — who steps down on May 29 after eight years in office — described the project as “a notable milestone” and “a game changer for the downstream petroleum products market, not only in Nigeria but for the entire African continent.”

The presidents of Ghana, Niger, Togo, Senegal and a representative of the Chadian leader were present at the commissioning.