US President George W Bush has signed into law a controversial energy bill which includes billions of dollars of tax incentives for oil and nuclear energy companies.
The legislation aims to improve energy efficiency by expanding renewable fuel sources and reducing domestic oil demand by a million barrels a day.
Critics say the measures will do little to reduce oil imports and simply provides tax breaks to US energy companies.
However, Mr Bush said the bill was only a first step in the plan to reform American energy production.
