Higher prices at the gasoline pump are making Americans nervous, and White House officials are concerned about the possible effects fuel prices might have on President Obama’s reelection campaign.

　　The president visited the University of Miami in Florida on Thursday to discuss the problem and his administration’s long-term plan to reduce U.S. dependence on foreign oil.

　　Obama told students that the price increases are mostly a result of events in other parts of the world.

　　“Oil is bought and sold in a world market.  And just like last year, the single biggest thing that is causing the price of oil to spike right now is instability in the Middle East, this time around Iran,” Obama said.

　　Jeff Mower, editor-in-chief of the New York-based Pratts Oilgram Price Report, agrees that the rise in U.S. gasoline prices is due largely to factors beyond America’s shores.

　　“Tensions surrounding Iran right now, problems over in Sudan, which is shutting crude production - all of this has helped to drive up the price of Brent crude and also gasoline prices,” Mower said.

　　Mower also says that lower profit margins have led oil companies to close some refineries outside of the United States, which is also driving up prices.

　　Opposition Republicans say that Obama is not doing enough to encourage domestic oil production.  At Wednesday’s Republican contender presidential debate, Newt Gingrich said increased drilling would lead to dramatically lower gasoline prices.

　　“If we would open up federal land and open up offshore, you would have $16-18 trillion - not billion-trillion - in royalties to the federal government in the next generation - an enormous flow, which would drive down prices to $2.50 a gallon, would help [U.S. federal] balance the budget and would create millions of jobs,”  Gingrich said.

　　Republicans have also criticized the president for postponing a decision on approving the Keystone Pipeline project, which would carry oil from Canada to U.S. refineries.

　　In Miami on Thursday, Obama ridiculed Republican criticism.  He said his administration has approved an unprecedented amount of domestic oil and gas production.  But, he said, more drilling alone would not solve the problem.

　　“It means that anybody who tells you that we can drill our way out of this problem does not know what they are talking about or just is not telling you the truth,” Obama said

　　The president again called for support for his comprehensive strategy to reduce America’s dependence on foreign oil.

　　“If we are going to avoid being at the mercy of these world events, we have got to have a sustained, all-of-the-above strategy that develops every available source of American energy.  Yes, oil and gas - but also wind and solar and nuclear and biofuels and more," he said.

　　Gasoline prices in the United States have reached an average of more than 92 cents per liter.  More than half of the Americans surveyed in a new public opinion poll say that price could exceed $1.32 this year.

　　Analysts say Florida, the nation's fourth-most populous state, will be a key battle ground in November's presidential election.  After his speech in Miami, Mr. Obama held several campaign fundraising events in Florida.