The chief executive of Russia's sovereign wealth fund has denied that forming closer energy ties with Saudi Arabia is about politically sidelining Washington.

Russia and Saudi Arabia are set to sign $3 billion in joint investments this week, according to the Financial Times. This includes a $1.1 billion agreement for Russian petrochemical company Sibur to build a plant in Saudi Arabia.

Speaking to CNBC at the Russian Energy Week, Kirill Dmitriev, CEO of the Russian Direct Investment Fund (RDIF), said a deepening of ties with Saudi businesses posed no threat to the U.S.

"Well, I think Russia and Saudi Arabia have lots of things in common. We want to diversify our economies away from oil and frankly, there was not much going on before.

"So, of course we are not talking about Russia being a substitute for the U.S. The U.S. will remain a key partner for Saudi Arabia for hundreds of years to come."