Western-imposed sanctions are disrupting Iran's oil exports - and further pressure could affect global oil markets, says a report by the Energy Information Administration, an analytical agency of the US Department of Energy.

­The West seems to be drowning itself with harsh economic measures levied against Iran in an attempt to punish it for a nuclear weapons program whose existence remains apocryphal. According to a bimonthly EIA report published Wednesday, sanctions are already undermining oil exports from the Islamic Republic, and further measures could tighten global oil markets that have already been hit by a rash of outages in other countries. The EIA, an independent arm of the Department of Energy, received input on the report from the departments of Treasury and State and the Director of National Intelligence.

Even before the sanctions take effect, American and European insurance companies are already finding it difficult to insure Iranian oil supplies as global oil prices are soaring, the EIA says.