Oil prices rose in early market trading after the US said it would blockade Iranian ports beginning Monday.
The price of US crude oil rose 8% to $US104.24 a barrel and Brent crude oil, the international standard, rose 7% to $US102.29.
Brent crude has swung dramatically during the Iran war, rising from roughly $US70 per barrel before the war in late February to more than $US119 at times. On Friday, ahead of the peace talks, Brent for June delivery fell 0.8% to $US95.20 per barrel.
Iran has been effectively controlling the Strait of Hormuz, a key waterway for global oil shipping.