Choosing money in the face of diplomatic pressure from the U.S., the government said Thursday it has struck a long-delayed deal with Tehran to grant a Japanese consortium rights to develop Iran's huge Azadegan oil field.

The $2 billion deal will give Japan access to one of the world's largest oil reserves. Dependent on imports for almost all its energy needs, Japan has been seeking its own source of stable crude oil since it lost its rights of negotiation in Saudi Arabia in 2000.

Iran would meanwhile gain much-needed foreign investment to become the second-largest producer within the Organization of Petroleum Exporting Countries.