The US and UK have agreed (ahead of the US fleet boosting its presence in the Gulf, and SWIFT cutting Iran off from the world's financial system) to release reserves of emergency oil stocks.
UPDATE
The Whitehouse are currently denying the veracity of this report. Meanwhile the "inaccurate" report has had the desired effect of driving oil prices lower.
Funny that!
FURTHER UPDATE
The Prime Minister's official spokesman re Obama Cameron talks has admitted that the issue was discussed:
"The issue of oil supply was discussed but no decisions were made."
You can rest assured that the decision has been been made, and will be implemented on a predetermined date/event.