Obama hits back at GOP 'Flat-Earthers' over rising fuel prices Mr Obama, whose approval rating sharply dropped this week amid intense media attention on the topic, dismissed claims from his would-be challengers that an increase in domestic drilling for oil could solve the problem. In America, we use more than 20 per cent of the world's oil. But even if we drilled in every square inch of this country, we still only have 2 per cent of the world's known oil reserves," said Mr Obama. He added that his administration had "quadrupled the number of operating oil rigs to a record high." The president insists that his energy plan is an "all-of-the-above" strategy, but he has been sharply criticised for declining to approve the Keystone XL oil pipeline from Canada across the US. Speaking on the campaign trail Mr Romney, a former Massachusetts governor, has mocked Mr Obama for his desire to invest in renewable energy, stating: "You can't drive a car with a windmill on it." He also likened his opponents to Rutherford B Hayes, the 19th president, who reportedly said of the telephone: "It's a great invention but who would ever want to use one?" In an interview on Thursday Mr Romney said that Mr Obama was "absolutely" responsible for the rise in petrol prices because of his reluctance to approve more drilling. "The world believes that America's not going to have the energy we need, and we're going to have to continue sending hundreds of billions of dollars out of our economy going into other nations," Mr Romney told Fox News.