Nick Spicer, Al Jazeera’s correspondent, in Washington DC, said: "It is fair to assume that they are discussing a limitation of liability.

"Undoubtedly this is about more than just the oil spill and the compensation. It has begun to affect the White House … politics in general.

"So it has been pointed out that Obama has to stand up."

Containment cap

BP said on Wednesday that it had begun burning off excess oil as well as siphoning off oil spewing from the well.

A containment cap placed on the ruptured well on June 3, has been collecting about 15,000 barrels per day for a week, but it is not stemming all of the oil flow into the Gulf of Mexico.

IN DEPTH

The cap followed several failed attempted to stop the leak.

On Tuesday a team of US scientists significantly revised its estimate of the oil flow rate, increasing it to 35,000-60,000 barrels (5.56 million litres to 9.5 million litres) a day.

The team initially estimated the flow at between 12,000 and 19,000 barrels per day (bpd); last week, it increased that estimate to 20,000 to 40,000 bpd.

All three figures are far above the initial estimate of 5,000 bpd given by BP and US officials at the start of the crisis.

The announcement came on the day Obama, in his first Oval Office address, vowed to make BP pay for the oil spill and outlined a "battle plan" to tackle the destruction caused by the leak.

"We will make BP pay for the damage their company has caused. And we will do whatever's necessary to help the Gulf Coast and its people recover from this tragedy," he said.

Additional resources

Obama said the government would offer additional resources and assistance to the affected coastal states as cleanup efforts continue.

He said that BP would be required to set aside money to pay for the long-term damage.

Obama used the bulk of his speech to renew his pitch for a switch from fossil fuels to clean energy, saying that Americans "must seize the moment" and "accelerate the transition".

Nearly two months after the oil spill began, many critics say Obama has not done enough to stop it.

A recent Associated Press-Gfk poll showed that 52 per cent of Americans were disssatisfied with the government's slow response to the spill.

The April 20 explosion at BP's Deepwater Horizon drilling rig killed 11 workers and ruptured the wellhead.

The spill has fouled 190km of US coastline, damaged multi-billion-dollar fishing and tourism industries, and killed birds, sea turtles and dolphins.