A containment cap placed over a damaged deepwater well is helping limit the amount of oil flowing into the Gulf of Mexico, U.S. Coast Guard Admiral Thad Allen says.

Oil is still escaping into the Gulf, but the cap allowed officials to recover more than 14,800 barrels in 24 hours, Allen said Tuesday.

The cap — which was placed over the BP well late last week after several failed attempts to stop the flow of oil — diverts oil to a tanker waiting on the water's surface, roughly 1,500 metres above.

"In the last four days, we've gone from about 6,000 barrels up to almost 15,000," Allen said.

Tens of millions of litres of oil have spilled into the Gulf since the Deepwater Horizon rig exploded 80 kilometres off the coast of Louisiana 50 days ago. There is no consensus on exactly how much oil is streaming out of the damaged well, but federal officials have estimated the flow could be between 12,000 and 25,000 barrels a day.

Allen, who called the spill a "catastrophe" for the region, said officials will be meeting with BP to assess how well it is handling claims for relief from people hurt by the spill.

Meanwhile, BP said it would spend the net revenues from oil recovered from its stricken Gulf of Mexico oil well to restore wildlife habitats in the Gulf Coast, CEO Tony Hayward said in a statement Tuesday.

"BP is committed to protecting the ecosystems and wildlife on the Gulf Coast.… Proceeds from the sale of oil recovered from the MC252 well will be used to further this commitment."

'I know whose ass to kick'

U.S. President Barack Obama defended his response to the massive oil spill, saying the White House is actively engaged in dealing with the worst oil spill in U.S. history.

Gas and oil continue to spew out of the Deepwater Horizon well in the Gulf of Mexico in this image taken from a BP live video feed on Tuesday. (BP/Reuters)

In an interview aired on NBC's Today show Tuesday, Obama said he's had many conversations about the spill with Gulf coast fishermen and experts.

"We talk to these folks because they potentially have the best answers — so I know whose ass to kick," the president said.

In the interview with Matt Lauer, Obama was also asked to comment on statements made by BP's Hayward, most notably, that he would like his "life back" and that the Gulf of Mexico is a "very big" ocean.

"He wouldn't be working for me after any of those statements," Obama said, noting that he has not spoken with Hayward directly.

Later Tuesday, the White House announced the president would make his fourth trip to the region next week. He will spend Monday and Tuesday inspecting damage in Mississippi, Alabama and Florida — three states where some of the oil has come ashore.

Many spills

On Monday, Allen said efforts to stop the leak and clean up what's already spilled will be a huge job that will continue long into the summer and fall.

"We are no longer dealing with a large monolithic spill," said the admiral heading the U.S. government's relief effort. "We have patches of oil going in a lot of directions. We need to adapt to meet the threat."

BP contract workers look through seaweed along the shore in Pensacola Beach, Fla., on Monday. (Marice Cohn Band/Miami Herald/Associated Press)

Cleanup efforts will continue long after the spill stops, he said. Two relief wells — widely thought to be the best hope of finally stopping the leak — should be completed by early August.

"Dealing with the oil spill on the surface will take a couple of months [after that]," he said. But he warned that it will take years to clean up contaminated marshlands.

The random, scattered nature of the oil was evident Monday during a trip across the state line between Alabama and Florida.

On the Alabama side, clumps of seaweed laden with oil littered beaches. Huge orange globs stained the sand in places. But at Perdido Key, on the Florida side, the sand was white and virtually crude-free. Members of a five-person crew had to look for small dots of oil to pick up, stooping over every few metres for another piece.

MoveOn, a U.S.-based advocacy group, said it is organizing oil spill vigils Tuesday to "demand an end to our dependence on oil, call for stepped-up efforts to end the spill, and stand in solidarity with all those affected in the Gulf."

With files from The Associated Press