BP boss Tony Hayward said he was doing "everything in his power" to stem the Gulf oil leak and that he had "no intention" of resigning after Barack Obama stepped up the pressure on the British oil giant.
Hayward, who is personally overseeing the firm's containment efforts, said: "We absolutely understand and share President Obama's sense of urgency over the length of time this complex task is taking.
"BP - working closely with scientists and engineers from across the whole oil industry, from government agencies and departments, and with local officials along the Gulf Coast - is focused on doing everything in our power to stop the flow of oil, remove it from the surface, and protect the shoreline."
The oil firm has deployed under-sea robots in the Gulf to try to thread a small tube into the jagged pipe that is spewing oil into the water a mile below the surface.
BP said it hoped to know later if the tube succeeded in taking the oil to a tanker at the surface.
Mr Hayward said the oil spill should not mean the end of deep-water exploration.
He told BBC Radio 4's Today programme: "I don't believe it should (result in a ban), in the same way as Apollo 13 did not stop the space programme nor have serious airline accidents from time to time stopped people flying."
But he said the leak would be a "transforming event for exploration and production activities in the deep water of the world, in particular the deep water of the United States.
"You can't have an incident of this seriousness and not expect significant changes as a consequence.
"What we need to do is ensure that the changes we make address the risk that has occurred here."
Mr Hayward added that he had "no intention" of resigning and said that no conclusions about responsibility for the disaster should be drawn until a formal investigation was completed.
He said that BP's efforts had been largely successful in "constraining the spill to the immediate vicinity of the leaking oil".
"Thus far, we have done a very good job of containment on the surface and very, very, very little oil is finding its way to the shore," he said.
Responding to President Obama's allegations of a cosy relationship between oil companies and regulators, Mr Hayward said: "The regulatory regime for the deep water offshore in the US is very rigorous, more rigorous than many other regimes and the industry has had a very good track record. It has been exploring in deep water for more than 20 years and has never to date had this sort of incident."