President Obama has said the huge oil spill in the Gulf of Mexico is a potentially unprecedented environmental disaster. And the British company BP will have to meet the cost of dealing with it. Mr Obama said his government would work to prevent further damage to the region, but he stressed BP was responsible.

"Let me be clear. BP is responsible for this leak. BP will be paying the bill. But as president of the United States, I'm gonna spare no effort to respond to this crisis for as long as it continues, and we will spare no resource to clean up whatever damage is caused. And while there'll be time to fully investigate what happened on that rig and hold responsible parties accountable..."