When asked if the federal government would consider a pause in offshore drilling, Deputy Secretary of the Interior David Hayes replied "Everything is on the table."

Hayes added that he believe the fundamental practices of offshore drilling are safe, but the administration was not limiting its possible policy response to the spill in any way.

Offshore industry bosses have been invited to the White House for a meeting later today to discuss this incident and safety procedures in the Gulf, Gibbs said.

Answers

The list of those invited includes BP and Macondo partner Anadarko, US supermajor ExxonMobil, Italian giant Eni and services giant Halliburton, who is understood to have had the cement contract on the Deepwater Horizon.

"When it comes to the safety of offshore personnel and protecting the environment, we want answers as much as anyone and will strive to fully cooperate during this response process," an Anadarko representative told Upstream, adding that Anadarko operations chief Al Walker would attend the meeting.

Congress was briefed on the incident last night.

After the briefing, Representative Henry Waxman called BP's response inadequate.

Emergency

Hayes refused to comment on Waxman's claim, saying only that the White House was closely and constantly evaluating the situation.

Louisiana governor Bobby Jindal has declared a state of emergency as the spill is projected to hit his state's southern coastline late tomorrow.

A group of Louisiana shrimpers and fishermen have already filed a pair of lawsuits over the spill, who claim BP, Transocean and Halliburton are responsible for damaging the $2.6 billion Louisiana seafood industry.

US government officials have revised estimates of the Macondo spill's volume to 5000 barrels per day - five times the original figure, as BP boss Tony Hayward appeared to be pushing the blame for the blowout on to contract drilling giant Transocean.

In an interview broadcast on CNN today, a clearly tired Hayward said: "The responsibility for safety on the drilling rig is with Transocean. It is their rig, their equipment, their people, their systems, their safety processes."

A Transocean spokesman declined to comment, saying only that the drilling giant "continues to work closely with our customer BP, as well as with the Coast Guard, the Minerals Management Service (MMS) and the unified command".

He added that Transocean "remains focused" on the task at hand.

Meanwhile the UK supermajor said there is a second breach in the marine riser just above the well's blowout preventer (BOP), which means oil is leaking from three sites on the riser.

Spew

US President Barack Obama has been briefed and the Department of Defence has now joined efforts to contain the spill in the Gulf of Mexico.

The revised spill estimate was made public by the US National Oceanic & Atmospheric Administration (NOAA).

While BP and the US Coast Guard think the original 1000 bpd estimate holds, Coast Guard Rear Admiral Mary Landry said NOAA experts believe the as much as 5000 bpd could spew into the Gulf.

“NOAA is telling me now they prefer we use 5000 bpd as an estimate for what actually has leaked from this well, and will continue to leak, until BP secures this source," she said.

“It has become clear, after several unsuccessful attempts to identify the cause of the leak, that it is time for BP to supplement their current mobilisation,” she added.

Impact

BP has welcomed an offer of assistance from the US Defence Department to help contain the massive slick, which now threatens the coasts of Louisiana, Mississippi, Alabama and Florida.

Speaking on NBC's Today show this morning, Doug Suttles, the chief operating officer of the supermajor's exploration and production unit said: "We'll take help from anyone, I mean we welcome the offer from the Department of Defence, we're working with the experts across the industry.

"We're not interested in where the idea comes from, what we're interested in is how do we stop this flow and how do we stop it now."

He told ABC's Good Morning America show: "I believe our plan can handle the spill".

"We're going to do everything we can to minimise the impact of this event," Suttles said.

As the operator of Mississippi Canyon Block 252, BP will pay for the clean-up costs.

Uncertainty

Earlier Suttles said the new breach in the riser is not the reason for NOAA's revised estimate for the volume of oil flow.

“We discovered a new point of leak,” Suttles said. “This leak is just beyond the top of the BOP in the riser.

“Given the location, we do not believe this changes the amount currently estimated to be released,” he added.

However, Suttles said he does not disagree with Landry’s 5000 bpd estimate, “which clearly is in the range of uncertainty”.

He added: “Actually the only thing we know for certain is what we see on the surface, given the inability to precisely measure the oil flow."

Efforts to close the well at the BOP with remotely operated vehicles (ROVs) have so far failed. Suttles said those efforts will continue nonetheless.

“Until we run out of options to try to stop the flow of oil at the BOP we won’t stop, no matter how unlikely we are to be successful,” he said.

Burn

Meanwhile, BP completed the first controlled burn of a small portion of the oil slick heading toward the Mississippi River delta.

Upstream was told the burn started at 4pm local time and ended at 4:45pm.

“We think we’ll see oil strike land some time before the end of the week,” Suttles said, adding that more boom will be deployed and otherwise they will “get ready to clean up oil if it reaches the beach”.

The Coast Guard has commenced an in situ burn yesterday to attack the slick.

A Coast Guard spokesman told Upstream the first controlled burn was lit yesterday at about 5pm local time.

Petty Officer Cory Mendenhall said oil was corralled into about 500 feet of fire-proof boom at a site 5 miles to 10 miles west of the spill and then lit.

Crews used a floating igniter – a container with fuel that is lit on fire – which was then pushed off the boat and allowed to float into the gathered slick.

Further burn-offs are expected to take place today.

The burn comes as the latest flow models show the spill contacting the Mississippi River delta late Friday.

Suttles said the results of the burn will not be immediately released.

The Coast Guard planned a series of small burns that will last about an hour a piece, each one fuelled by several thousand gallons of oil.

Endorsed

Former Minerals Management Service (MMS) offshore safety boss Bud Danenberger endorsed the idea, saying it had been used effectively in the past.

"This is definitely the way to go, and is not a new approach," he told Upstream.

"They did a trial burn at Exxon Valdez (first day) that worked great," he said. "They would have burned the rest the next day, but an overnight storm dispersed the oil. The rest is history."

The burn plan was endorsed by Texas General Land Office commissioner Jerry Patterson, who sent a special fire-proof boom for the job.

The MMS said it is in contact with other operators in the area of the sheen and no production has been shut in as a result of the slick

Despite high hopes for the burn, which could consume as much as 90% of the oil it contacts, most of the spill will still be treated with traditional methods like skimming and dispersants.

Kill

The decision to burn off the slick comes as it emerged BP is spending more than $6 million per day to contain the spill, which started after an explosion on the Transocean semi-submersible rig Deepwater Horizon last Tuesday.

Transocean’s semi-submersible rig Development Driller III will spud a relief well on Friday.

Development Driller III was already under contract to BP in Mississippi Canyon Block 778, where it was working on the Thunder Horse South development, according to MMS information.

The well will be spud about half a miled from the Macondo well, in Mississippi Canyon Block 252, and will attempt to intercept the wellbore close to its total depth of 18,000 feet.

Once that is accomplished, heavy fluids will be pumped downhole, followed by cement, to kill the well.

The MMS has already approved the permits submitted for drilling the relief well, MMS regional director Gulf of Mexico region Lars Herbst said.

BP has said the well would take two to three months to drill and is expected to cost about $100 million.

Meanwhile, the UK supermajor is fabricating components to connect a subsea oil recovery system to Transocean’s drillship Discoverer Enterprise in order to collect oil leaking from Macondo and store it within the rig’s storage tanks.

Mechanism

The structure was already completed at the Wild Well Control yard in Port Fourchon, Louisiana but crews continue work on the equipment needed to connect the structure to the Discoverer Enterprise.

The Discoverer Enterprise is capable of receiving 20,000 barrels per day and can store over 125,000 barrels within its hull, Suttles said.

The oil will then be offloaded using the 300,000 barrel Overseas Cascade shuttle tanker, which was recently converted for Brazilian operator Petrobras.

BP expects to deploy this recovery system within two to four weeks. The same system has been used in shallow water, but never in the deep-water Gulf.

“The issue is to make certain it can withstand the pressure of the much deeper water at the side and to be able to sort out the various topsides processing issues,” BP chief financial officer Byron Grote said in an analysts call earlier this week.

Attempts to shut off the flow through the BOP with an ROV have not been successful, Suttles said, but those efforts will continue with eight different ROVs.

'Dead man system'

Suttles said the ROV was able to hook up a hydraulic hose to the BOP to trigger the closing mechanism but it did not close.

Herbst told a briefing earlier this week it is unknown why the Cameron BOP did not automatically close, which under one system he referred to as the “dead man system” is supposed to occur when hydraulic and electronics to the BOP are lost.

BP spokesman Daren Beaudo confirmed that the company had contracted three ROV support vessels, each carrying a pair of ROVs; Ocean Intervention III from Oceaneering, Boa Sub C which is on long-term charter to Aker Marine Contractors and Skandi Neptune from Subsea 7.

The Macondo well - a discovery well which was to be temporarily abandoned ahead of later completion as a subsea producer - blew out late last Tuesday evening.

The well had been drilled to 18,000 feet when an explosion rocked the semisub before the rig was engulfed in flames. The semisub sank on Thursday morning, extinguishing the blaze.

Salvaged

A senior Transocean executive, Adrian Rose, said the company had not begun to determine if the rig, which was found in 5000 feet of water Saturday, could be salvaged.

Transocean has said the rig was insured for up to $560 million.

The initial cause of the accident is still unknown, although Rose earlier indicated it seems likely the well blew out.

“We don’t know what caused the accident,” he said. When asked if the incident involved a blowout, he replied: "Basically, yes."

Eleven of the 126 crew on board the Deepwater Horizon at the time of the explosion are missing, presumed dead.

Drilling giant Transocean has confirmed nine of its employees are among the missing. Two worked for services outfit Smith International and Schlumberger's M-I Swaco joint venture.

BP holds 65% of the Macondo prospect and operated the well. US independent Anadarko holds a 25% working interest and Japan's Mitsui holds the remaining 10%.