President Barack Obama said on Tuesday that he would have fired BP Plc chief executive Tony Hayward for underestimating what has become the biggest oil spill in US history.
The White House said that Obama, himself under pressure for a perceived slow federal response to the crisis, will travel to the Gulf Coast region again next week to get a first-hand view of clean-up efforts.
Obama has already made three visits to Louisiana since the Deepwater Horizon rig exploded April 20. Monday and Tuesday, the president will visit the three other Southern states affected by the disaster: Mississippi, Alabama and Florida.
As the oil disaster entered its 50th day, Obama said that Hayward's early statements that the massive leak at the bottom of the Gulf of Mexico would have a modest impact on the region's ecosystem were grounds for his ouster.
Hayward provoked anger when he told Gulf Coast residents last month that "I would like my life back" - seen as insensitive to the families of the 11 workers who died in the rig explosion and for local fishermen whose livelihoods are threatened by the ongoing disaster.
Hayward "wouldn't be working for me after any of those statements", Obama said in an interview with US broadcaster NBC. Hayward has said there is no talk of him leaving his post.
BP has faced growing anger over its failed attempts for weeks to cap the ruptured well.
Obama, too, has been criticised for his response to the disaster. Tuesday he suggested much of the disaster's effects could be mitigated within three years, a timeline scientists consider overly optimistic.
UN Secretary General Ban Ki-moon called on governments to recognise the value that oceans play in the world's ecosystem and implement better safeguards against man-made damage.
"The diversity of life in the oceans is under ever-increasing strain. Over-exploitation of marine living resources, climate change and pollution from hazardous materials and activities all pose a grave threat to the marine environment," Ban said in a statement.
The oil spill could bring long-term damage to the Gulf's fertile ecosystem. Obama said he was confident that the region would "bounce back" from the crisis.
"Potentially we can preserve those estuaries and marshes so that three years from now, things have come back, things have bounced back," Obama told NBC.
Scientists expect the damage to last much longer. Professor Thomas Shirley of Texas A&M University said Obama's forecast was "wildly optimistic".
"We don't really know how long things are going to last here," Shirley said, noting that the spill could wipe out a number of endangered species in habitats in and around the Gulf waters.
Obama has ordered a halt to all deepwater oil drilling until safety standards can be studied and improvements implemented.
Meanwhile, a containment cap that BP placed over the ruptured well last week has shown some success. The dome-like structure collected nearly 15,000 barrels of oil Monday from the leaking pipe about 1.6 km below the surface, Coast Guard Admiral Thad Allen, who is leading the government's response, said Tuesday.
It remains unclear just how much oil is spewing daily from the ruptured well. Estimates have ranged from 12,000-30,000 barrels.
BP said on Tuesday it would donate net revenue from the sale of any oil collected into a wildlife fund for the region. The company has faced complaints for failing to quickly pay out claims for damages filed by Gulf residents who are unable to work because of the spill.
Government scientists on Tuesday confirmed the existence of at least two undersea oil plumes below the surface in the Gulf of Mexico.
The plumes were found up to 1 km deep, one nearly 80 km north-east and another about 260 km south-east of he leaking wellhead.
The plumes had low concentrations of oil, but "that does not mean that it does not have a significant impact," said Jane Lubchenko, chief of the government's National Oceanic and Atmospheric Administration.