Mele Kyari, NNPC's group chief executive, said President Bola Tinubu has "re-engineered the security approach. We've already seen very significant changes in our production environment", Reuters reported.

Africa's top oil producer recorded an average daily oil output of 1.22 million barrels per day (mbpd) in the second quarter of 2023, the National Bureau of Statistics said a week earlier.

Large-scale oil theft from pipelines and wells has hobbled the country's output and crimped exports in recent years, damaging Nigeria's finances and leaving Tinubu with one of his biggest challenges.

Tinubu, who has embarked on Nigeria's boldest reforms in decades, scrapped a costly but popular subsidy on petrol that cost the country $10 billion last year. The central bank, under Tinubu, has also lifted foreign exchange trading restrictions.

Kyari said Nigeria would have been spending about 1 trillion naira ($1.3 billion) monthly on the subsidy "in today's market conditions", he said, adding that petrol consumption is down 30% to 46 million litres after the subsidy removal.

He added that foreign exchange demand for petrol imports has also declined.

"We simply don't have those resources anymore. We're not just saving money, we're also facing realities around what we can afford," Kyari said.

Nigeria's oil sector is yet to contribute positively to the country's economic growth, which slowed to 2.51% in the second quarter, due to years of underinvestment, crude-oil theft and pipeline vandalism.

In the second quarter, the dominant oil sector which accounts for the bulk of government revenue and 90% of foreign-exchange reserves, contracted 13.43%.