The US is starting to break its "addiction" to foreign oil as high prices, more efficient cars, and the use of ethanol significantly cut the share of its oil imports for the first time since 1977.

The country's foreign oil dependency is expected to fall from 60 per cent to 50 per cent in 2015, before rising again slightly to 54 per cent in 2030, according to the head of the Department of Energy's statistical arm.