Exxon Mobil will deliver one million tonnes of crude oil annually under a long-term contract signed with Poland's oil company PKN Orlen.

"For the first time in history PKN Orlen has concluded a long-term contract for the supply of crude oil from the US,” Orlen's CEO Daniel Obajtek wrote on Twitter. “The contract with Exxon Mobil provides for the delivery of one million tonnes of crude oil annually to our refineries in Poland, the Czech Republic and Lithuania."

Obajtek added that the contract is one more step towards the diversification of Orlen’s supply sources.

Currently, Orlen Group refineries receive crude from Saudi Arabia, Russia as well as from the North Sea, Angola and Nigeria, the company wrote in a press release.