The crisis in the Gulf of Mexico is threatening to poison ties between US and UK. US president Barack Obama has compared the Gulf of Mexico oil spill to an environmental 9/11, as he prepares to meet top BP executives later this week. The president is making his fourth visit to the affected Gulf Coast and will address the nation from the Oval Office before sitting down with the BP executives for talks, which the White House says, will be "very frank". Obama plans to use the BP oil spill to urge Congress to pass new energy legislation. Meanwhile a Congressional investigation has found that BP took risky shortcuts in drilling the oil well, which has caused the spill.