Abu Dhabi: Global demand for crude will bring more balance to the oil market as soon as next year even with Iran preparing to increase output says Opec secretary-general Abdalla El-Badri.

"The expectation is that the market will return to more balance in 2016" El-Badri said while speaking at Abu Dhabi International Petroleum Conference and Exhibition (Adipec) 2015 in the capital. "We see global oil demand maintaining its recent healthy growth. We see less non-Opec supply."

El-Badri said he was "very happy that Iran is back" referring to the Opec member's steps to boost output once sanctions are lifted from its economy. Iran and the rest of Opec "can work together" to accommodate additional Iranian crude. "We can do anything for Iran no problem" El-Badri said without elaborating.

Demand will rise by about 17 million barrels a day to almost 110 million barrels a day by 2040 with 70 per cent of the growth to come from Asia he said. Oil tumbled more than 48 per cent last year as US stockpiles and production expanded creating a global oversupply that the International Energy Agency estimates will persist until at least the middle of 2016.

Meanwhile the UAE's Energy Minister Suhail bin Mohammed Faraj Al Mazroui said oil prices are unsustainable at current levels and will rise gradually as international companies defer projects and production plans.

"We have a vested interest to keep prices as stable as possible but we cannot do that by reducing production" Al Mazroui said. "We expect the market will recover by itself because high cost production will continue to decline."

The Opec's strategy to defend market share has exacerbated the oil glut as the group which kept its production target unchanged at 30 million barrels a day at the last meeting in June exceeded the ceiling for the past 17 months.