US President Barack Obama sounded a note of worry Saturday after BP's latest bid to halt the "enraging" Gulf of Mexico oil leak failed, warning the new plan underway was risky.
Hours after the British energy giant announced its "top kill" method over the past several days to try and cap and cement the ruptured well head was being abandoned, and a day after he visited the US Gulf Coast, Obama expressed concern that none of the attempts to plug the leak have been successful.
"While we initially received optimistic reports about the procedure, it is now clear that it has not worked," Obama said in a statement after speaking with top officials about the situation on the sea floor and along the US Gulf Coast.
All eyes have now turned to a new method in which engineers plan to sever the ruptured riser pipes from the well head and then fit a containment structure over the leak, allowing the oil to be syphoned to a ship on the surface.
"This approach is not without risk and has never been attempted before at this depth" of 5,000 feet (1,500 meters) Obama said.
"That is why it was not activated until other methods had been exhausted. It will be difficult and will take several days."
Obama stressed that his administration "will continue to pursue any and all responsible means of stopping this leak" until two relief wells currently being drilled are completed. They are expected to be done by August.
"From the beginning, our concern has been that the surest way to stop the flow of oil -- the drilling of relief wells -- would take several months to complete."
Obama, on Friday visited Louisiana to assure Gulf Coast residents that he was keenly focused on efforts to contain the leak and clean up the worst oil spill in US history.
"As I said yesterday, every day that this leak continues is an assault on the people of the Gulf Coast region, their livelihoods, and the natural bounty that belongs to all of us," he said.
"It is as enraging as it is heartbreaking, and we will not relent until this leak is contained, until the waters and shores are cleaned up, and until the people unjustly victimized by this manmade disaster are made whole."