Oil prices rose Thursday as worries over a dispute between the world's leading powers and OPEC-member Iran over its nuclear program trumped rising crude stockpiles in the United States. U.S. light crude for May ended up 73 cents at $69.35 a barrel, $1.50 from the all-time record hit last August. London Brent crude for the new front-month June contract jumped 82 cents to a record $70.68 a barrel. Attention is still focused on Iran, which said late on Wednesday it would not back away from sensitive nuclear work after announcing earlier this week it had enriched uranium to a level used in nuclear power stations. "Our answer to those who are angry about Iran obtaining the full nuclear cycle is one phrase, we say: Be angry and die of this anger," President Mahmoud Ahmadinejad said on Wednesday, in comments reported by the official IRNA news agency. United Nations diplomats said the Security Council was unlikely to take substantive action on Iran before the end of April, when it receives a report from the International Atomic Energy Agency (IAEA). The IAEA's leader, Mohamed ElBaradei, said in Tehran Thursday he could not confirm Iran had successfully enriched the uranium, but has called on the Islamic state to suspend enrichment and return to diplomatic negotiations. The tensions in the world's fourth largest crude exporter added to the fear of fuel shortages as demand surges into the summer driving season and worries over a loss of around a quarter of Nigeria's gasoline-rich crude to rebel attacks. Thursday's gains erased a decline in oil prices Wednesday after the U.S. government reported an increase in crude stockpiles to the highest in eight years. Crude stocks in commercial storage in the United States rose by 3.2 million barrels last week to 346 million barrels, more than twice the rise forecast in a Reuters poll and the highest level since May 1998, U.S. Energy Information Administration (EIA) data showed.