President Barack Obama took his push for increased federal investment in clean energy on the road Thursday, telling crowds in Las Vegas and at a Colorado military base that America must be able to compete in a global growth industry of coming decades.

Earlier Thursday, the federal government announced plans to sell off oil and gas leases on 38 million acres of the Gulf of Mexico seafloor in a new domestic energy push.

The leases could yield as much as 1 billion barrels of oil and 4 trillion cubic feet of natural gas, the Interior Department estimates. The scheduled sale in June will be the second since the Deepwater Horizon disaster of 2010 when nearly 5 million barrels of crude spewed into the Gulf.

Obama mentioned the planned lease sales in his remarks at Buckley Air Force Base in Aurora, Colorado, which has a 1-megawatt solar array and last year test-piloted jets that run on advanced biofuels.

"We are the Saudi Arabia of natural gas," he told the military crowd in detailing his strategy to increase domestic oil and gas development while promoting investment and innovation in clean energy development.

His energy proposals come amid criticism from Republicans and the oil industry for the administration's rejection of a permit to build a pipeline to transport oil from Canada's tar sands production in northern Alberta to the Gulf of Mexico.

Obama has said the permit was rejected because Republicans forced a decision before there was time for a necessary review of a proposed route change requested by Nebraska officials, including the state's Republican governor. The president also said the rejection was due to timing, rather than the merits of the project that would create several thousand jobs for the two-year construction period.

In his remarks earlier Thursday at a UPS facility in Las Vegas, Obama called his energy plan an "all-out, all-in, all-of-the-above strategy that develops every available source of American energy."

Among other things, Obama promised more federal assistance for local governments to upgrade their automotive fleets while also pushing new tax incentives for cleaner corporate vehicles.

The president also said the administration is working to develop up to five highway natural gas corridors, and he announced a new competition to encourage the development of breakthroughs for natural gas vehicles.

"We've got to keep at it. Think about what could happen if we do," Obama said. "Think about an America where more cars and trucks are running on domestic natural gas than on foreign oil. Think about an America where our companies are leading the world in developing natural gas technology and creating a generation of new energy jobs. ... We can do this."

The president's remarks came on the second day of a three-day road trip building on themes announced in Tuesday night's State of the Union address.

On Wednesday, Obama discussed the importance of core American values and fairness in the tax code during stops in Iowa and Arizona. He's planning to highlight education and college affordability during a visit Friday to Ann Arbor, Michigan.

All five states -- Arizona, Colorado, Iowa, Michigan and Nevada -- are considered politically critical to the president's re-election hopes in November.

During his stop in Las Vegas, Obama also echoed his tax fairness mantra, once again warning that the Bush-era tax cuts can't be maintained without sacrificing either fiscal stability or critical domestic programs.

"Do we want to keep these tax cuts for the wealthiest Americans? Or do we want to keep investing in everything else -- like education and clean energy, a strong military and care for our vets? Because we can't do both," he said.

"If I get tax breaks I don't need and the country can't afford, it either adds to our deficit or takes away from someone else, whether it's a senior, a student or a family trying to get by. That's not right. That's not who we are."

In the State of the Union address, Obama called for a 30% tax rate on people earning more than $1 million a year, saying it was wrong for the wealthy to pay a lower rate than ordinary workers. One of Obama's possible opponents in November, multimillionaire and former Massachusetts Gov. Mitt Romney, revealed Tuesday he paid less than 15% in taxes last year on income derived mostly from investments.

For their part, Romney and the other GOP presidential contenders accuse Obama of misguided proposals that would worsen the economy for middle-class Americans.

On energy issues, the White House said Thursday that Obama will push for greater use of cleaner-burning natural gas as an automotive fuel for trucks and buses, and new support for renewable energy sources such as solar or wind power.

In addition, the administration also will open up public lands to renewable electric projects aimed at producing enough power for 3 million homes.

The oil and gas leases up for sale in June include the remaining, unclaimed areas off Louisiana, Mississippi and Alabama, ranging from as close as three miles from the coast to up to 230 miles offshore. The minimum bid for deepwater leases will be $100 per acre, according to the Interior Department.

It is working on plans for a dozen more lease sales through 2017, which it estimates will open up three-quarters of the recoverable oil and gas below the outer Continental Shelf -- reserves Obama pledged to open up in his State of the Union speech.

Supporters say more energy exploration will bring more jobs for Americans still reeling from the steepest economic downturn in decades. But some critics remain wary of the risks illuminated when the drilling rig Deepwater Horizon blew up and sank in April 2010, killing 11 men aboard and uncorking an undersea gusher that took three months to cap.

"We've got oil continuing to wash up. We've got ongoing restoration needs down there that haven't been addressed yet," said Aaron Viles, a spokesman for the New Orleans-based Gulf Restoration Network.