The US deputy Treasury Secretary, David Cohen said the downward trend of oil prices in recent days and weeks has cost the Iranian regime to lose billions of dollars during the negotiation period until July 1. He added that if the price of oil remains at the current level, the Iranian regime would lose about $11billion during the next 6 months of the negotiation with the P5+1. The price of oil in world market has lost half of its value since last summer.