US President Barack Obama has strongly criticised BP's chief executive Tony Hayward over the massive oil spill in the Gulf of Mexico.
In an interview with NBC, Mr Obama was asked about comments Mr Hayward made in the wake of the disaster, such as "I want my life back" and the Gulf is "a big ocean".
Mr Obama said: "He wouldn't be working for me after any of those statements."
He said he had visited the Louisiana coast "so I know whose ass to kick".
The interview on NBC's Today show is to be broadcast later on Tuesday.
Mr Obama used the interview to defend his role in dealing with the crisis. Polls suggest that many Americans think he has handled the disaster poorly.
The president has made three visits to the oil-hit coast since the disaster started in late April, talking to fishermen and oil spill experts.
"I was down there a month ago before most of these talking heads were even paying attention to the Gulf," Mr Obama told NBC.
"I don't sit around just talking to experts because this is a college seminar, we talk to these folks because they potentially have the best answers - so I know whose ass to kick," he said.
Mr Obama told reporters he was committed to seeing the Gulf region restored to a condition better than it was before the Deepwater Horizon rig exploded and sank on 20 April, killing 11 workers.
The leaking wellhead is currently spewing out between 12,000 and 24,000 barrels of oil per day. Some 11,000 barrels of oil are being trapped by a containment cap.
Meanwhile, police are protecting Mr Hayward's family at their home in Kent in southern England after they received hate mail and threatening phone calls.
Maureen Hayward told the Daily Telegraph, a British newspaper, about the growing hostility towards her and their two children.
"Members of my family have had nasty phone calls and we have also had mail from groups," she was quoted as saying.
"Tony is obviously away and we are miles away from him so it's upsetting," she said.
There is an "ongoing police operation" involving Mr Hayward's family home, the newspaper quoted local police sources as saying.
BP - and in particular Mr Hayward - has received widespread criticism over the handling of the spill. At one point, Mr Hayward said "the environmental impact of this disaster is likely to be very, very modest".
The New York Daily News has called him "the most hated and clueless man in America".
Meanwhile, US Coast Guard chief Adm Thad Allen has said that cleaning up marshlands would take a long time.
Adm Allen, the co-ordinator of the clean-up operation, told reporters it would take "a couple of months" to clear the oil slick from the surface of the Gulf.
But he said: "Long-term issues of restoring environments and habitats will be years."
He said BP needed to do better at getting money to people and businesses affected by the spill.
He said that while BP had nearly doubled the amount of oil being funnelled from the leaking wellhead since Friday, it was now "trying to increase that production rate, close the venting valves and move to a greater capacity".
He said BP was hoping to move a second production platform into the area to increase the amount of oil that could be siphoned off.
Adm Allen added that BP was also preparing a bigger rig to process a greater capacity of oil in severe weather. The region's hurricane season started last week.
White House spokesman Robert Gibbs warned, however, that collecting oil through the containment cap fixed over the leaking well remained a risky operation.
BP said on Monday that the cost of its response to the disaster in the Gulf had reached about $1.25bn (£860m).
This number does not include $360m for a project to build six sand berms to protect Louisiana's wetlands from the spreading oil, BP has said.
Oil from the Deepwater Horizon spill has been found on beaches and wetlands along more than 100 miles (161 km) of coast from Louisiana to the Florida Panhandle.