 US President Barack Obama, under pressure from Republicans and the public to bring down petrol prices, announced new measures yesterday to expand domestic oil production in alaska and the Gulf of Mexico. High fuel prices have dented Obama s ratings in opinion polls and threaten to dampen the economic recovery that is critical to his re-election in 2012.  The president has pushed for reducing US oil consumption and expanding renewable energy while also focusing on domestic oil and gas production   which Republicans want to expand dramatically.