When trading opened at midnight Monday, North Sea oil rose. Shortly after opening, the price was $93.11 per barrel in futures trading.
Futures for U.S. WTI oil rose to $89.50 per barrel.
When trading closed on Friday, the prices were $91.12 and $87.36 per barrel, respectively.
On Friday, President Donald Trump said he was set to "make a final decision" on a proposal to extend the ceasefire and take steps to reach a permanent end to the conflict.
Then it went silent. According to American media, a revised proposal has been sent back to Iran.
The war has created a global energy crisis. Before it began on February 28, oil cost around $70.
