"We've made a very thorough commitment, we are going to clean up this spill, we take responsibility"
"Those responsible will be held accountable," he said.
BP is already facing a string of multi-million-dollar lawsuits in Louisiana, Alabama and elsewhere accusing it of negligence and failing to take adequate precautions to prevent such a spill occurring.
The plaintiffs include fishermen, shrimpers, seafood distributors, and restaurants, but also tour and fishing boat operators, whose livelihoods are directly threatened by the oil slick.
BP, which has spent millions of dollars in recent years trying to present a cleaner, more environmentally-friendly image of the company, has said it is committed to cleaning up the spill and minimising the damage caused.
Faced with a mounting disaster, the company faces an uphill task trying to defend its public image in line with its corporate tagline as a company that goes "beyond petroleum".
Nonetheless, public relations experts say BP has done a better job than US rival Exxon in the aftermath of the 1989 Exxon Valdez tanker spill in Alaska.
In response to the Gulf of Mexico spill, BP has held regular news conferences and has devoted a large section of its website to the clean-up effort. It says more than 2,500 staff have been deployed to manage the crisis.
Speaking to Al Jazeera on Saturday, Neil Chapman, a BP spokesman, said the company had a number of efforts under way "attacking the source" of the spill on the sea bed, with teams of people working on several different methods of containing the oil.
He said work was ongoing using robotic submarines to try and get a so-called blowout preventer valve to work, while at the same time another team was working to build a system to capture the oil under the surface.
Meanwhile, planes have been dropping chemical dispersants on the slick from the air, while ships have been deployed to try and skim the oil from the sea or contain it within kilometres of floating booms.
Chapman said BP had also tried a new technique where dispersants were injected right into the flow on the sea bed to mix with the oil.
"We've made a very thorough commitment, we are going to clean up this spill, we take responsibility, we're desperately sorry and all our experts are working as hard as they can to shut off the oil at source," he said.
|A massive effort is under way to try to contain the oil and minimise its impact [AFP]
His comments came following the emergence of a 2009 document in which BP officials downplayed the possibility of a catastrophic accident at the Deepwater Horizon well.
The 52-page exploration plan and environmental impact analysis, filed with the federal Minerals Management Service, says repeatedly that it was unlikely, or virtually impossible, for an accident to occur that would lead to a giant crude oil spill and serious damage to beaches, fish, mammals and fisheries.
Pressed about the report, BP's spokesman said the kind of disaster which occurred on the rig, leaving 11 workers dead, had been unforeseeable.
"No-one would have foreseen this sort of event happening where there was a catastrophic event on the surface... and then systems failed as they did," he said.
"What we've got to do is learn the lessons. There've been a number of investigations launched and eventually it will be discovered what happened.
"At the moment the focus is on shutting in the source and defending the shores."