The head of Russia’s sovereign wealth fund, Kirill Dmitriev, said on Monday that the joint agreement between OPEC and its other oil producers allies to increase production indicates the strength of the Russian-Saudi alliance in the energy field, which will help stabilise the market for many years to come.

Reuters quoted Dmitriev, who participated in the drafting of the initial agreement between Moscow and OPEC in December 2016, saying that “a long-term partnership between Russia and Saudi Arabia regarding the coordination of efforts between oil producers and the establishment of a new organisation in the future based on cooperation between OPEC and independent partners, would contribute to overcoming differences between producers and developing a unified business strategy for world markets.”

He added that “long-term cooperation between Russia and Saudi Arabia would ensure stable pricing in the world markets and increase investments in the energy sector.”

Read: OPEC looks set to increase oil production by 1 million barrels per day

Last week, Dmitriev said in a meeting with Russian President Vladimir Putin that Saudi Arabia had agreed to invest 10 billion dollars in Russia, including two billion dollars already spent.

The Russian official predicted that investment between the two countries will double in the next three years.

The Organisation of the Petroleum Exporting Countries (OPEC) has agreed with a number of other big crude producers to increase production by about one million barrels per day starting from July, after Saudi Arabia convinced its rival Iran to cooperate.

Before OPEC’s meeting in Vienna, Saudi Arabia and Russia, the world’s largest oil producers, announced that there was a general consensus to “institutionalise” the formula of cooperation between OPEC and independent producers, and extend it until 2019 and beyond so as to monitor the market and change production if necessary.