BP mounted a more aggressive response to the oil spill in the Gulf of Mexico as it deployed undersea sensors to better measure the ferocious flow of crude while drawing up new plans to meet a US government demand that it speed up the containment effort.
The financial ramifications of the disaster which began on April 20 are growing by the day as the White House and states put pressure on the oil giant to set aside billions for spill-related claims in a move that could quickly drain the company's cash reserves and hasten its path towards possible bankruptcy.
BP was also trying to meet a deadline to respond to a letter from the US Coast Guard demanding that it intensify the efforts to stop the spill. One of the actions BP took was to use robotic submarines to position sensors inside the well to gauge how much oil was spilling.
Scientists have not been able to pin down just how much oil is leaking into the Gulf, although the high-end estimates indicated the spill could exceed 100 million gallons. The government has stressed that the larger estimates were still preliminary and considered a worse-case scenario.
The Obama administration's point man on the oil spill, Admiral Thad Allen, said government officials thought the best figures wee from a middle-of-the-road estimate, which would put the spill at around 66 million gallons of oil. That is about six times the size of the Exxon Valdez spill. BP is currently capturing about 630,000 gallons of oil a day, but hundreds thousands more are still escaping into the Gulf.
The company has said that it could begin siphoning an additional 400,000 gallons a day from tomorrow by burning it using a specialised boom being installed on a rig - and any new success would be welcome news for US president Barack Obama as he returns to the Gulf. Mr Obama is due to arrive in the Gulf for a two-day visit that will be followed by a nationally-televised address and a meeting with BP executives on Wednesday.
The crisis has already become a crucial test for the Obama presidency as it takes a greater toll on his image with each day that more oil gushes into the sea. "We're at a kind of inflection point in this saga, because we now know that, what essentially what we can do and what we can't do, in terms of collecting oil, and what lies ahead in the next few months," senior adviser David Axelrod said on NBC's Meet The Press.
"And he wants to lay out the steps that we're going to take from here to get through this, through this crisis."
Mr Obama wants an independent, third party to administer an escrow account paid for by BP to compensate those with "legitimate" claims for damages. The amount of money set aside will be discussed during talks this week between the White House and BP, but the request will most definitely be in the billions.
Louisiana's treasurer has said it wants nearly £3.5 billion and Florida said it wanted £1.7 billion.