(CNN) -- Saying BP has "from day one, frankly not fulfilled the mission it was supposed to fulfill," Interior Secretary Ken Salazar expressed frustration Sunday with the delay in stopping an underwater oil gusher 33 days after an oil rig exploded and sank in the Gulf of Mexico.

"I have no question that BP is throwing everything at the problem," Salazar said. "Do I have confidence that they know exactly what they're doing? No."

But he and other federal officials likened the task to an "Apollo 13" mission.

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Marcia McNutt, director of the U.S. Geological Survey, told reporters that while BP has failed to meet its own schedule for stopping the gusher, their schedule was probably not feasible from the outset given that the tasks involve construction, mobilizing equipment and fabricating devices.

"I think everyone has to understand that the kinds of operations they're doing in the deep sea have never been done before," said McNutt, who is helping lead a team of scientists from the Department of Energy, NASA and others in helping find a solution to the leak.

Salazar and Homeland Secretary Janet Napolitano will lead a bipartisan Senate delegation to the region Monday, authorities said. Lisa Jackson, Environmental Protection Agency administrator, was headed to Louisiana on Sunday.

Oil has been spewing into the Gulf since late April, when the drill rig Deepwater Horizon -- which BP was leasing from rig owner Transocean -- exploded and sank about 40 miles off Louisiana.

BP has estimated oil is flowing out of the well, located beneath 5,000 feet of water, at the rate of about 5,000 barrels a day (210,000 gallons). However, some have estimated the flow rate far higher, and critics have claimed BP is attempting to downplay the spill, its magnitude and possibly its effect on the environment.

Speaking from BP headquarters in Houston, Texas, Salazar said Sunday, "I am angry and I am frustrated that BP has been unable to stop this well from leaking and to stop the pollution from spreading. We are 33 days into this effort and deadline after deadline has been missed."

Initially, BP said it would attempt to kill the spewing well, some 5,000 feet below the surface, on May 18, Salazar said. "That has not yet happened."

The team of scientists, he said, is a team of "all-stars." "If there is a way to kill this well, they will find it. If there is a way to stop this pollution from spreading, they will find it."

Earlier Sunday, BP's managing director defended his company against a perceived lack of credibility, insisting that "nobody is more devastated" by an underwater oil gusher in the Gulf of Mexico.

"All of us at BP are trying to solve the problem," Robert Dudley said on CNN's "State of the Union." "... We've been open about what we're doing."

Asked about comments made by Rep. Ed Markey, D-Massachusetts, who alleged BP has "lost all credibility," Dudley said. "Those words hurt a little bit."

"We are all united in wanting the same result," McNutt said, referring to BP and the federal government. "We want to stop polluting the ocean, and we want to kill this well. We are all on the same page about that."

But Salazar pointed out the explosion and subsequent spill was "never supposed to happen in the first place," and occurred because of the failure of safety measures designed to prevent such an incident.

If the government finds out that BP is "not doing what they're supposed to be doing, we'll push them out of the way appropriately, and we'll move forward to make sure everything is being done to protect the people of the Gulf Coast, the ecological values of the Gulf Coast and the values of the American people," he said.

Later this week, BP will attempt to execute a so-called "top kill," in which thick, viscous fluid twice the density of water is pumped at a high rate into the site of the leak to stop the flow so the well can then be sealed with cement.

If the top kill does not work, the company will try a "junk shot," which would involve plugging the well with rubber and other substances, Dudley said. "And then we've got a third step we can take. It's something called loss circulation material."

McNutt pointed out, however, possible complications remain as far as the top kill. "Don't think we're out of the woods yet," she said.

Dudley told CNN the rate of oil flow is imprecise, comparing it to popping a soda can and measuring the rush of gas and soda that comes out.

BP is looking at a variety of options to permanently stop the flow of oil, he said. "We've got the best minds on this."

"There's a series of options here," Dudley said. "I believe that activity will begin either late Tuesday or at dawn on Wednesday, because we need daylight. There is no certainty at these kind of depths. But we all want it to work. And we've all got steps that we'll put in place immediately if it doesn't."

"We're going to keep trying to shut off this well," he said. "We're not going to wait until August," when a relief well that could allow the leaking well to be closed off will be completed.

On BP's credibility, U.S. Coast Guard Commandant Adm. Thad Allen told "State of the Union":

"When I give them direction or the federal on-scene coordinator gives them direction, we get a response. I've got (BP CEO) Tony Hayward's personal cell phone number. If I have a problem, I call him. Some of the problems we have had that we've worked through are more logistics and coordination issues."

Asked whether he trusts the company, Allen said, "I trust Tony Hayward. When I talk to him, I get an answer."

But, shown a clip of Hayward's recent comments on Britain's Sky News in which he said the environmental impacts of this disaster is likely to be "very, very modest," Allen said, "Obviously, they are not modest here in Louisiana."

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"We need to be putting all hands on deck there. And we don't want to perpetuate any kind of notion at all, whether it's BP or the United States government, that this is anything less than potentially catastrophic for this country," he added.

On BP's flow estimates, "I've said from the start, I don't think anybody can know to a virtual certainty how much oil is coming out of that pipe down there. ... From the start, we deployed resources in anticipating a catastrophic event."

"There's great frustration and we all understand it, particularly the president," White House spokesman Robert Gibbs told CNN Sunday, "but everything that is humanly possible is being done to cap this oil well from leaking oil and for dealing with the spread of the oil on the surface and underneath the surface right now."

In response to Crowley's question on whether a long-term fix could elude officials until August, Dudley said the company will put another containment device over the top of the well to recover the oil if no other options pan out.

Asked whether he would call the spill catastrophic, Dudley said, "Oh, Candy, absolutely. You see the films of the oil washing on some of the beaches in Louisiana. This is catastrophic for, well, every employee of BP. It is catastrophic for the 24,000 people down there working on the spills that we've let some get through these defenses."

He pledged the company is doing all it can to clean up the spill and stop the leak, but acknowledged that the spill will leave lasting damage.

"We will undoubtedly measure and investigate the effects of this spill for many, many years to try to determine and learn the long-term impacts on this. We are committed to both cleaning it up, studying it, understanding it."

"In terms of not trusting BP, there's nobody -- nobody -- who is more devastated by what has happened and nobody that wants to shut this off more than we do and learn what happened so this never happens anywhere, to anyone anywhere in the world again," he said.

Also, Louisiana officials Sunday demanded the federal government approve their plans to dredge up walls of sand to protect delicate inland estuaries.

They said the Army Corps of Engineers and agencies overseeing the spill have been slow to respond.

