High crude oil prices have had some impact on U.S. economic growth but the pain is not on the level seen during the energy price shocks of the 1970s, U.S. Energy Secretary Sam Bodman said on Wednesday.

I am surprised that we have not in the past seen more of an effect on our economy from these high oil prices, Bodman told reporters in an interview. The impact of oil on the economic performance of the United States is not what it once was ... 30 years ago.

At some point in time clearly it will have more of an effect than it has already, Bodman said as he headed toward a tour of a wind turbine manufacturing plant.

Federal Reserve Chairman Ben Bernanke testified before Congress in July that a tripling of energy prices has cut economic growth by 0.5 percent to 1 percent over the past few years. U.S. crude oil futures remain close to July's $78.40 a barrel record high.

But the record inflation-adjusted average monthly price that U.S. refiners paid for imported crude oil was $87 a barrel in January 1981, according to the Energy Department.

Bodman said that there would clearly be an impact on crude oil prices if exports from Iran were cut, but he reiterated that the world's consumer nations are prepared to deal with such a cutoff by using their strategic oil stocks.

There would clearly be dislocations, there would clearly be an increase in prices, Bodman said.

A stand-off over Iran's nuclear program also supported prices. President Mahmoud Ahmadinejad has insisted on Iran's right to produce nuclear fuel, responding to a U.N. resolution demanding that Tehran stop its atomic work by Aug 31.

Iran is the world's No. 4 oil exporter, and the dispute has helped lift the price of oil 21 percent this year.

Bodman said world oil producers including Iran and Venezuela were dependent on revenues generated by oil exports, which makes disruptions less likely.

I tend to be optimistic that they're going to continue to want to get paid, Bodman said.