President Barack Obama awaited a firsthand update on the Gulf Coast oil spill as two members of his Cabinet on Sunday outlined the "very grave" environmental impact and sought to counter criticism the government had reacted slowly.
Homeland Security Secretary Janet Napolitano said the administration had treated the explosion at the BP rig April 20 as a potential disaster from the beginning.
"The physical response on the ground has been from day one as if this could be a catastrophic failure," she said. "Every possible resource was being lined up on shore."
Interior Secretary Ken Salazar said it was uncertain when the oil, spewing from a pipe nearly a mile beneath the water, would be plugged.
"The scenario is a very grave scenario. You're looking at potentially 90 days before you ultimately get to what is the ultimate solution," said Salazar. But then "a lot of oil could spread."
Obama flew to Louisiana for briefings on the underwater spill, which remained unstopped and impossible to measure, raising fears it could be pouring more oil into the Gulf than earlier believed. Traveling with him were White House chief of staff Rahm Emanuel, homeland security and counterterrorism adviser John Brennan and energy adviser Carol Browner.
The Coast Guard estimated that at least 1.6 million gallons of oil have spilled since the April 20 explosion that killed 11 workers on an offshore rig. In the Exxon Valdez disaster, an oil tanker spilled 11 million gallons off Alaska's shores in 1989.
Obama has relied on reports from agency chiefs and Coast Guard officials since the magnitude of the spill became clear late Wednesday. Aides report he's been getting regular updates.
Salazar, Napolitano and the administration's point man on the disaster, the commandant of the Coast Guard, Adm. Thad Allen, made the rounds of the Sunday talk shows to defend the federal response.
Allen said it is impossible to know the eventual size of the spill because that will depend on when BP can stop the flow, a technically challenging effort hampered by the well's depth where everything must be done by remote control.
"On the level of complexity, I'd certainly give it nine," said Allen on "State of the Union" on CNN. "We have to stop this oil where it's emanating on the sea floor."
BC Chairman Lamar McKay said the company is "throwing every resource that we've got" at trying to plug the well, calling that the No. 1 priority. Drilling a relief well is expected to take as long as three months, but McKay said a dome, which would be lowered to the sea floor to cover the leaking wellhead, will be ready to be deployed in six to eight days. Such an approach has been used in other well blowouts, but never at a depth of 5,000 feet.
"We're doing everything possible that we know of,' said McKay on ABC's "This Week."
McKay rejected criticism that his company's safety record played a role in the rig explosion and subsequent massive oil spill. "I believe we've got a failed piece of equipment," he said, referring to the mechanism that was supposed to shut off the well on the sea floor in event of a well blowout.
While no cause has yet been determined for the accident, Salazar also said there "is no doubt at all" that the blowout safeguard mechanism -- know as a blowout preventer -- was defective. He said the devices are being inspected at other oil rigs in the Gulf.
But Salazar dismissed suggestions that any of the other 30,000 drilling rigs in the Gulf should be shut down because of the issue.
"For us to turn off those spigots would have a very huge impact on America's economy right now," said Salazar on ABC's "This Week." Despite the BP spill, which threatens to grow into one of the country's worst environmental disasters, "this is an industry that can operate safely," he said.
Obama has said no new offshore oil drilling leases will be issued unless rigs have new safeguards to prevent a repeat of the explosion that unleashed the massive spill.
The spill came just weeks after Obama announced plans to open up large areas of the Eastern Seaboard and a part of the Gulf for possible future oil drilling. And it's led to increasing calls to reconsider that initiative by environmentalists and coastal state lawmakers.