President Bush said Wednesday the nation must accelerate exploratory oil drilling and make greater use of natural gas and coal resources.

Saying the United States remains too heavily dependent on foreign oil more than 15 years after the energy shortage that produced long gas lines in 1974, Bush told a joint session of the Texas Legislature: "We need a national energy policy that relies not only on oil but on many other sources."Bush, who set himself up in the Texas oil business in the late 1940s and became a millionaire before entering public life, said in his prepared remarks, "I know there are still a few dark clouds remaining on our economic horizon."

But he said Texas is showing signs of recovering from the business slump brought about by the decline of the energy industry in recent years, and this has happened because an increasingly diversified economy has brought tens of thousands of high-tech jobs to the state.

"Still, no matter how diversified and high-tech Texas has become, a strong domestic energy industry is important to the future of this state and all of America," Bush said. "I find it disturbing that nearly 50 percent of America's oil is imported. This is not good for our national security."

Maximizing use of oil resources will make the country less dependent on imported fuel, he said, and increasing reliance on alternative energy resources will give the country a cleaner environment.

The president reiterated that the nation must not retreat from oil exploration because of the huge spill from the tanker Exxon Valdez off the coast of Alaska.

"We are using federal resources intelligently in the cleanup effort," he said. "We are working with industry to develop an improved plan in the event of a future spill."

"But shutting down our domestic energy production is no answer and would merely increase our dependence on foreign oil," Bush said.