"Our dependence on foreign oil is like a foreign tax on the American dream, and that tax is growing every year," Mr. Bush said at the Virginia BioDiesel Refinery.
The visit to this plant 96 miles from the White House was another effort by Mr. Bush to step up pressure on the Senate to follow the lead of the House and pass his national energy plan, which provides tax breaks for those using alternative fuels.
Biodiesel is cleaner burning and American-made, but carries a higher price tag than regular diesel fuel. It is often blended with conventional transportation fuels as an extender.
Before his speech, the president got a demonstration of how biodiesel is made — and how cleanly it burns in an engine. Mr. Bush was given a white handkerchief that had been held on an exhaust pipe of a revved-up 18-wheeler, and deemed it clean enough to hold up to his nose.
"Biodiesel is one of our nation's most promising alternative fuel sources and by developing biodiesel you're making this country less dependent on foreign sources of oil," he said.
"Americans are concerned about high prices at the pump and they're really concerned as they start making their travel plans, and I understand that," the president said. "I wish I could just wave a magic wand and lower the price at the pump. I'd do that. But that's not how it works."
He said the high prices confronting consumers have been decades in the making.
Mr. Bush urged Congress to enact energy legislation that he says addresses both supply and conservation issues in a bid to make the United States less dependent on foreign nations, particularly those in the volatile Middle East, for its energy needs.
Mr. Bush has attempted to set an August deadline for Congress to get a bill to his desk. The House has approved a plan with many elements that the president wants, though he opposes the billions in tax breaks and subsidies to energy companies that it contains. The Senate has yet to act on alternative legislation.
Mr. Bush's plan would open an Alaska wildlife refuge to oil drilling as part of its attempt to address supply problems.
His focus Monday, though, was on the part of the plan that boosts support for conservation and fossil fuel alternatives — such as hydrogen, biodiesel and clean coal technology. Separately, Mr. Bush has also offered proposals to speed construction of nuclear power plants and oil refineries.
Monday's appearance was one of three this week, in Washington and around the country, that are designed to turn Mr. Bush's focus back to his chief domestic priorities after a foreign trip. Later in the week, Mr. Bush was pushing his free-trade agenda, particularly a pact with Central American and Caribbean nations, and his proposals to remake and strengthen Social Security.