NEW YORK (CNN/Money) - Environmental groups launched a new attack on sport/utility vehicles and Detroit automakers Wednesday, charging that lack of progress on more fuel-efficient vehicles could be responsible for future U.S. wars in the Middle East.

Watch the ad for the dream vehicle that Detroit refuses to build, according to the Natural Resources Defense Council and the Detroit Project. Play video (QuickTime, Real or Windows Media)

Two environment groups -- the Natural Resources Defense Council and the Detroit Project -- argue that America needs an SUV that can get 40 miles per gallon, but say the problem is that "Detroit won't build it."

"It could take America to work in the morning without sending it to war in the afternoon," the two groups say of such an SUV in an ad, which is set to appear in Detroit, Washington, New York, Los Angeles, San Francisco, San Jose, Philadelphia, and Tampa-St. Petersburg. The groups will spend about $300,000 to run the ads.

The groups argue that U.S. automakers are not doing enough with voluntary programs to improve fuel economy. They argued that if SUVs and other vehicles got 40 mpg, it would allow the United States to stop importing oil from the Middle East and cut off financial support for governments that support terrorism against it.

"Detroit is waving a white flag instead of an American flag. They have surrendered the battle for energy security," said NRDC attorney Robert F. Kennedy Jr. "It's time for sensible standards that put existing technology on the road in every car, truck and SUV."

Arianna Huffington, author and co-founder of the Detroit Group, and Jason Vines, president of SUV Owners of America, debate the vehicle's fuel efficiency and the latest environmentalist-sponsored ad. Play video (QuickTime, Real or Windows Media)

U.S. automakers responded Wednesday that they're doing what they can to improve fuel economy, and that they're moving ahead with plans to introduce SUVs with hybrid gas and electric engines that get a 40 percent improvement in fuel economy, or better, over existing models, letting them reach the 40 mpg target set by the groups.

General Motors Corp. (GM: Research, Estimates) said its Saturn VUE hybrid SUV will be available in 2005. Ford Motor Co. (F: Research, Estimates) said it will offer a hybrid Escape SUV for fleet customers by the end of this year, and for consumers next year.

But the automakers said they can't force consumers to pay for the more fuel efficient vehicles. "We don't have any guarantees people are going to buy it," Ford spokesman Mike Moran said. "It has to be market-driven."

GM said it will roll out a fleet of 12 fuel-efficient demonstration vehicles in Washington Thursday, including four with fuel cells, which run on hydrogen and have only water vapor as their exhaust. Those vehicles will be made available to government officials, journalists and other Washington opinion makers over the next year for demonstrations, but GM says it doesn't expect to have commercially viable fuel cell vehicles available until 2010.

"We've got a short-, mid- and long-term technology plans to help us increase fuel efficiency which are also good from business perspective," said GM spokeswoman Joanne Krell. "We would say we're giving customers what they want to buy."

The environmentalists say they support research into fuel cells, but more needs to be done now to improve fuel economy.

"Fuel cells are a terrific long-term solution," Kennedy said. "But we have an energy security problem now, and we need solutions now. Car companies are blaming American consumers for a scandal that starts in Detroit and ends in Washington."