Oil prices have jumped after Qatar's energy minister warned he expects all oil and gas exporters in the Gulf to stop production within days.
Saad al-Kaabi told the Financial Times the conflict in the Middle East - a region which plays a key role in global energy supplies and shipping routes - could "bring down the economies of the world".
Brent crude oil rose to $89.17 a barrel on Friday, up 4.4% from the end of trading on Thursday.
If ships were unable to proceed through the Strait of Hormuz, Kaabi said that in two to three weeks the price of oil could soar much further to $150 a barrel.
About a fifth of the world's oil supply is usually shipped through the Strait of Hormuz each day, but traffic through the narrow passage has all but halted since the US-Israel war with Iran began last weekend.
