Oil prices have surged after several of the world’s largest oil exporters announced surprise cuts in production.
The price of Brent Crude oil jumped by more than $5 a barrel, or 7%, to above $85 as trading began.
The increase came after Saudi Arabia, Iraq and several Gulf states said on Sunday they were cutting output by more than one million barrels a day.
Oil prices soared when Russia invaded Ukraine, but are now back at levels seen before the conflict began.
However, the US has been calling for producers to increase output in order to push energy prices lower.