Washington (CNN) -- British Prime Minister David Cameron said Tuesday that he "completely understands" the anger that "exists ... across America" regarding the oil well operated by BP that exploded in the Gulf of Mexico three months ago.
"It is BP's role to cap the leak" and compensate people affected by it, he said during a visit to Washington to meet with President Obama. Cameron said he is in regular touch with the leadership of BP, a British-based company.
Just down Pennsylvania Avenue from the White House on Tuesday, a former interior secretary said Interior Department regulators designing disaster contingency plans didn't prepare for a calamity the size of the current Gulf of Mexico oil spill crisis because of a lack of precedent.
Dirk Kempthorne told a joint congressional subcommittee on the three-month anniversary of the spill that previous environmental impact statements, assessments and oil spill response plans were "based on the probability that a significant oil spill was small."
"When the 2007 and '12 five-year plan was written, there had not been a major oil spill in 40 years," he said. "One very real consequence of the Deepwater Horizon accident is that these historical assumptions will be forever changed." Kempthorne pointed out that Congress had the power to review and reject that plan, but chose to allow it to proceed.
He added that the repercussions from BP's ruptured oil well in the Gulf of Mexico "will forever change the offshore energy industry. Never again will a Cabinet secretary take office and be told that more oil seeps from the seabed than has been spilt from drilling operations in U.S. waters. Never again will decision makers not include planning for events that might be low-probability events, but which, in the unlikely event they occurred, would be catastrophic."
Two House subcommittees held the joint hearing Tuesday to investigate the role of the Interior Department in the Deepwater Horizon disaster. Legislators are trying to figure out who's responsible for the crisis and how better government regulation of energy producers might help avert such disasters in the future.
Kempthorne and Gale Norton, who preceded him as interior secretary under President George W. Bush, showed up at the beginning of the session to testify. Current Interior Secretary Ken Salazar appeared for testimony during a second session after a lunch break.
Salazar testified that he expects the moratorium on deepwater drilling in the Gulf of Mexico to remain effective until as late as November 30.
"Give the dynamic situation in the Gulf of Mexico and the issues that I outlined earlier, from our point of view, it would be [irresponsible] to take our hand off the pause button as many have suggested," Salazar said.
Salazar countered some of Kempthorne's comments, saying the administration has worked tirelessly to kill the oil well and devise policies to prevent such an incident in the future.
The beginning of the hearing consisted of several lawmakers lobbing partisan broadsides against the opposing party's administration. House Energy and Commerce Committee Chairman Henry Waxman, D-California, was one of the few to acknowledge fault on both sides of the aisle.
"Today, we're going to examine the role of the regulators," Waxman said. "We will learn that the Department of Interior under both President Bush and President Obama made serious mistakes. The cop on the beat was off duty for nearly a decade, and this gave rise to a dangerous culture of permissiveness."
While lawmakers in Washington debate the causes of the crisis, people across the Gulf region were working on solutions.
Scientists were weighing a new option for permanently sealing it.
The "static kill" would involve pumping mud into the well to force oil back into the reservoir below, officials from BP said Monday, noting that the option could succeed where similar attempts have failed because pressure in the well is lower than expected.
Geologist Arthur Berman said on CNN's "American Morning" on Tuesday that the relative simplicity of a static kill makes it an attractive option for BP.
"I think the reason that they're considering it is because they've yet to intercept the well bore," Berman said. "They're very close, a few feet away with the relief well, as everyone knows. But to actually intersect the 7-inch pipe does involve a bit of technology and accuracy, whereas if they do the static kill through the existing well bore at the top, there's less uncertainty about their ability to actually get the mud into the pipe."
No visible oil has flowed from the well since July 15, when BP closed all the valves in the new custom-made cap that was installed July 12. Federal officials said Tuesday that one reported leak is coming from another old well a couple miles away and is inconsequential.
Energy Secretary Steven Chu refused to comment on the proposed static kill. He said the Obama administration is assimilating the constantly evolving information about the crisis to "try and formulate plans going ahead that will bring the ultimate stopping of the leak as quickly as possible, at the same time trying to minimize oil spillage."
BP Senior Vice President Kent Wells told reporters that the static kill idea was still "very much in its infancy," but a decision could be made in several days.
A static kill and the relief well could "work in tandem to have an ability to have the well completely killed in less time," Wells said Tuesday afternoon. Workers may be able to put casings in one of the relief wells Wednesday and Thursday, he said.
Former Coast Guard Adm. Thad Allen, the federal government's point man on the spill, on Tuesday extended pressure testing of the capped well for yet another 24 hours and said discussions of the static kill are ongoing.
Allen said workers will complete the final casing for the relief well before any static kill would be tried.
A tropical depression around the Leeward Islands is being watched carefully. Gale-force winds could affect the well site in the coming days, Allen said.
Allen will accompany Vice President Joe Biden to Theodore, Alabama, on Thursday to check on oil spill cleanup efforts and meet with Gulf residents.
CNN's Eric Fiegel and Vivian Kuo contributed to this report.