Shortly after opening, the price of North Sea oil is up 1.6 percent, while WTI oil is up 2.0 percent.
Before the US and Israel's war against Iran began on February 28, oil cost around $70 per barrel.
US President Donald Trump is trying to talk down the prices with both carrots and bombastic warnings. Now his threat to attack Iranian oil facilities has been rumbling since Wednesday night.
Iran has managed to completely block transport in the Strait of Hormuz, where about a fifth of the world's oil normally passes.
The rising oil price is causing inflation, higher costs and putting a stranglehold on stock markets and GDP growth around the world.
