US President Barack Obama has acknowledged that cleaning up the Gulf oil spill was an enormous challenge.
Mr Obama said the government had begun gathering vessels and equipment to deal with the clean-up from the first days of the accident.
He stressed there were no simple solutions to the spill and admitted the US government does not have the technology or expertise and must rely on oil company BP.
BP Chief Executive Tony Hayward has said progress is being made in choking off the five-week-old leak that has already spewed millions of gallons (litres) of oil into the Gulf.
Tony Hayward said it would be another 48 hours 'before the company will know if it has worked', adding that the chance of success remains at 60- 70%.
Mr Obama insisted yesterday that he is in charge of efforts to shut down what is now estimated as the worst oil spill in US history.
Meanwhile, BP resumed its mud-pumping operation yesterday evening after pausing its attempt to plug the oil leak, saying it wanted to monitor the effects of the 'top kill' procedure.
Watch the operation live
The vast oil slick caused by the explosion of BP's Deepwater Horizon rig has become the worst spill in US history, easily surpassing the Exxon Valdez environmental disaster in 1989, according to US government figures.
The new estimates put the flow rate at 12,000 to 19,000 barrels a day, much higher than the previous estimate of 5,000 barrels.
It means that between 18.6m and 29.5m gallons of oil have seeped into the Gulf - far more than the roughly 11m gallons of crude spilled in the Exxon Valdez disaster off Alaska.
President Obama yesterday announced a six-month extension of a moratorium on permits for new deepwater oil drilling while a commission investigates the causes of the disaster.
He also ordered 33 deepwater exploratory wells in the Gulf of Mexico to suspend work while they meet new safety requirements.
