In a televised address, U.S. President Barack Obama says BP must compensate those harmed as a result of the company's recklessness. (Alex Brandon/Associated Press)

U.S. President Barack Obama says he will not let those affected by the oil spill in the Gulf of Mexico lose their livelihoods, adding that BP must pay compensation and the United States needs to embrace a clean-energy future.

In a televised address to the country Tuesday night, Obama vowed his administration would fight the spill "with everything we've got for as long as it takes," adding that in the coming days and weeks, 90 per cent of the leaking oil would be captured.

But he said owners of shops and hotels in the region have a "wrenching anxiety that their way of life may be lost."

"I refuse to let that happen," Obama said. "Tomorrow, I will meet with the chairman of BP 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."

This compensation fund will be controlled by an independant third party, Obama said.

There also needs to be a long-term plan to restore the region, he said.

He announced that he has asked former Mississippi governor Ray Mabus to develop a long-term Gulf Coast restoration plan — to be funded by BP — in concert with local states, communities, fishermen, conservationists and residents "as soon as possible."

A national commission has been established to probe the cause of the disaster and recommend additional safety and environmental standards, he also said.

The spill is a reminder that drilling for oil these days entails greater risk and the U.S. has ignored the urgency to end its addiction to fossil fuels, Obama said.

"The tragedy unfolding on our coast is the most painful and powerful reminder yet that the time to embrace a clean-energy future is now. Now is the moment for this generation to embark on a national mission to unleash American innovation and seize control of our own destiny."

Obama said there are costs in transitioning to clean energy but the U.S. can't afford not to change "because the long-term costs to our economy, our national security and our environment are far greater."

But Obama did not provide specifics on how that should be accomplished, saying that he's "happy to look at other ideas and approaches from either [political] party."

More than 600 million litres of oil have gushed into the Gulf of Mexico from a broken wellhead since a BP-leased drilling rig exploded and sank on April 20, according to BP's estimates. Eleven workers were killed.

Government scientists said Tuesday that between 5.65 million and 9.5 million litres a day are leaking into the Gulf of Mexico.

Earlier estimates put the upper limit of the spill at 8.3 million litres a day.

"The improved estimate is based on more and better data that is now available, and that helps increase the scientific confidence in the accuracy of the estimate," said the Deepwater Horizon incident command team.

Scientists measured the leak using high-resolution videos shot by underwater robots, acoustic technologies, measurements of oil being collected and pressure measurements inside a containment dome placed over the wellhead.

Approval drops: poll

A new poll suggests a majority of Americans disapprove of how their president has handled the oil spill, though far more blame BP for what people call a sluggish two-month response.

The Associated Press-GfK poll, released Tuesday, found that 52 per cent of those surveyed do not approve of Obama's handling of the spill, a significant increase from last month when a significant chunk of Americans withheld judgment. But Obama's overall job performance rating did not suffer, staying virtually the same at 50 per cent.

That is consistent with the public's attitudes throughout his young presidency: people generally like him but don't necessarily agree with his policies.

A stunning 83 per cent disapproved of BP's performance in the aftermath of the rig's explosion, the poll found.

The AP-GfK Poll was conducted June 9-14 by GfK Roper Public Affairs & Corporate Communications. It involved interviews on landlines and cellphones with 1,044 adults and has a margin of sampling error of plus or minus 4.3 percentage points.

With files from The Associated Press