United States President Barack Obama has likened the Gulf of Mexico oil spill to an environmental 9/11 and says it will fundamentally alter the way his country thinks about energy.
Mr Obama, who is visiting Mississippi, Alabama and Florida for the fourth time since the spill began, called on his Democratic Party and other supporters to back a campaign for clean energy, adding that the US must "embrace a new future".
"Beyond the risks inherent in drilling four miles beneath the surface of the Earth," he said, "our dependence on oil means that we will continue to send billions of dollars of our hard-earned wealth to other countries every month - including many in dangerous and unstable regions.
"In other words, our continued dependence on fossil fuels will jeopardise our national security. It will smother our planet. And it will continue to put our economy and our environment at risk.
"We cannot delay any longer, and that is why I am asking for your help."
Investors fear dividend suspension
BP says the containment cap placed on the seabed well earlier this month has recovered 134,000 barrels of crude - but oil continues to gush out.
The containment system gathers only about 28,000 barrels a day, and the company's operation to boost that rate to between 40,000 to 50,000 barrels is not currently scheduled to be ready until July.
With the cost of cleaning up the spill put at $US1.6 billion ($NZ2.3b), and BP's share price still falling, investors are worried that the company may succumb to political pressure in the US and suspend its quarterly dividend to shareholders.
The company's directors are meeting to discuss that option.
In a meeting with the chairman of BP at the White House on Wednesday, Mr Obama is expected to demand that the oil company establish an account (to be administered by an independent third party) to fund damages claims.