WASHINGTON (CNN) -- GOP presidential hopeful John McCain called global warming and energy dependence a "serious and urgent" challenge Monday and said it directly threatens America's national security, in a speech at the Center for Strategic and International studies in Washington.

"The world is already feeling the powerful effects of global warming, and far more dire consequences are predicted if we let the growing deluge of greenhouse gas emissions continue, and wreak havoc with God's creation," The Arizona Republican said.

"It is a serious and urgent economic, environmental and national security challenge," he added. "National security depends on energy security, which we cannot achieve if we remain dependent on imported oil from Middle Eastern governments who support or foment by their own inattention and inequities the rise of terrorists or on swaggering demagogues and would be dictators in our hemisphere."

Saying he wasn't for a "grab bag of handouts to this or that industry," McCain said his strategy relies instead on "the genius and technological prowess of American industry and science," and called for a wider use and development of energy-saving technologies -- including energy efficient light bulbs, fuel-efficient cars, and nuclear power.

"Government must set achievable goals, but the markets should be free to produce the means," McCain said. "And those means are within our reach."

McCain, who has been campaigning for the Republican presidential nomination since early January, embarks on his official five-state announcement tour this week.

-- CNN Ticker Producer Alexander Mooney