Barack Obama has vowed to "make BP pay" for the damage caused by the Gulf of Mexico oil spill, in his first national address from the Oval Office.
The US president said he would meet company executives later and tell them that they must set up a fund to compensate those affected by the spill.
He described the spill as an assault on the shores and citizens of the US that tested the limits of human technology.
Presidents use the Oval Office for what they regard as vital national issues.
The speech comes as opinion polls suggest a majority of Americans disapprove of how Mr Obama has handled the crisis - the worst environmental disaster in US history. 'Mutual goals'
In his speech, Mr Obama likened the spill to an "epidemic" and reiterated that BP would be made to pay for the damage.

"We will fight this spill with everything we've got for as long it takes," he said.
Mr Obama said he would meet BP Chairman Carl-Henric Svanberg on Wednesday and "inform him that he is to set aside whatever resources are required to compensate the workers and business owners who have been harmed as a result of his company's recklessness".
In response to the speech, BP said in a statement that it shared Mr Obama's goal of cleaning up the oil and helping the people affected by the spill.
The firm said it was looking forward to Wednesday's meeting "for a constructive discussion about how best to achieve these mutual goals".

Lack of detail
Mr Obama also used the speech to renew calls for the US to embark on a future of clean energy.

"I say we can't afford not to change how we produce and use energy - because the long-term costs to our economy, our national security, and our environment are far greater," he said.
But he gave few details and made no pledges about specific legislation, instead promising to look at ideas from Republicans and Democrats on the issue.
He also announced that the national commission he set up to investigate the causes of the oil spill would be headed by Ray Mabus, a former governor of Mississippi.
With this speech, the president has made a lofty appeal to American idealism, analysts say, but that appeal will not be universally welcomed at a time when Americans are mostly worried about the more pressing need simply to stop the leak.
The Republicans were quick to criticise the address, with party chairman Michael Steele accusing Mr Obama of exploiting the crisis for his own political gain.

Tumbling share price
Oil has been spewing into the Gulf of Mexico since a drilling rig leased by BP exploded on 20 April.

The explosion killed 11 workers, and the rig sank two days later.
BP managed to place a cap over the leaking oil pipe earlier this month, and is now siphoning off much of the oil.
But estimates of how much oil was gushing out of the well before the cap was put in place have risen dramatically.
Initially experts said about 15,000 barrels were leaking each day, but scientists now believe the figure to be between 35,000 and 60,000 barrels.
US Congressmen have been fiercely critical of BP, accusing its executives of failing to follow proper procedures.
Politicians have spoken of legal action - and even the possibility of criminal charges - against BP.
As the rhetoric has become increasingly bitter, the firm's share price has continued to tumble, with billions of dollars being wiped off its value.