Abu Dhabi: The Organisation of Petroleum Exporting Countries (Opec) will continue to hold meetings in the coming days and weeks between its member countries and other non-Opec oil producers, according to Opec's secretary general, Mohammed Barkindo.

Speaking on Monday in Abu Dhabi, Barkindo said it was "vital" that Opec and non-Opec members cooperate and consult in order to rebalance the oil market.

His statement comes after Opec committed at a meeting in Algiers in late September to cut oil production to around 32.5 million barrels per day.

During his speech on Monday, Barkindo highlighted challenges in the energy industry over 2015 and 2016, saying that investments in energy have been on the decline. The secretary general said investments dropped by 25 per cent in 2015 and by 22 per cent in 2016.

The combined drop in both years is valued at well over $300 billion. Barkindo pointed that there has never been a three-year consecutive decline in history, and this led Opec to what he called a "landmark agreement" in Algiers in September.

His speech came during the opening ceremony of Abu Dhabi International Petroleum Exhibition and Conference (Adipec).

Also speaking at the event was Suhail Al Mazroui, the UAE'S Minister of Energy, who said oil prices have reached the bottom of the cycle.

Oil prices have more than halved since summer 2014 when they fell from their $115 highs to just below $50 this quarter.

Adipec runs until Thursday at the Abu Dhabi National Exhibition Centre.