High seas churned up by Hurricane Alex will delay deployment of a third containment vessel over the ruptured Gulf of Mexico oil well until next week, an official warned.
The White House meanwhile said it would within days roll out a decision on a revised six-month moratorium on offshore drilling, as President Barack Obama called his disaster management team to the White House to discuss next steps.
National Incident Coordinator Thad Allen said the Helix Producer ship had been delayed, as the outer bands of Alex, which battered Mexico, hinted at possible disruption that future, closer hurricanes could cause in the Gulf.
"We will need about three days after the weather calms... for that vessel to be able to hook up to the flexible coupling that it would be required to do," Allen said.
"So we're looking at somewhere around midweek next week to bring the third production vessel on-line." The vessel had originally been due on station by the end of June.
Once operational, the Helix Producer should be able to double the amount of oil being captured from the ruptured well to around 53,000 barrels per day.
An estimated 35,000 to 60,000 barrels per day has been gushing out of the ruptured well since the BP-leased Deepwater Horizon drilling rig sank on April 22 some 50 miles (80 kilometers) off the coast of Louisiana.
Two other containment ships were still operational despite seven-foot (two-meter) swells, capturing a portion of the escaping oil at a rate of about 25,000 barrels per day.
Allen also said that the storm, a glancing blow from the heavy weather whipped up by Alex, which battered Mexico but was downgraded to a tropical storm earlier Thursday, had significantly hampered on-shore and near-shore skimming operations to stop oil reaching beaches.
"The small vessels that do the skimming have a difficult time operating out there. We had to pull them back," Allen said, adding that some oil may have penetrated deeper on shore than normal.
Some patches of oil may have however been broken up by the agitated waters.
Around 428 miles (689 kilometers) of US shorelines have now been oiled as crude spews into the sea at an alarming rate, 10 weeks into the worst environmental disaster in US history.
Allen also said that progress was slightly ahead of schedule on the operation to drill two relief wells which will eventually be used to seal the ruptured Deepwater Horizon gusher.
But the target date is still in August, said Allen, who appeared at the White House in a civilian suit, one day after officially retiring from the US Coast Guard as an admiral.
The Coast Guard, backed by the Environmental Protection Agency (EPA) meanwhile issued a new directive and specific guidelines to BP Thursday on how the company recovers oil and other contaminated materials from the region, including requirements on transparency for what the firm does with the waste.
The EPA also announced results of toxicity tests on controversial dispersants used by BP to breakdown the oil.
None of the chemicals, said the agency, "displayed biologically significant endocrine disrupting activity," but it said BP was still being directed "to use dispersants responsibly and in as limited an amount as possible."
The White House vowed last week to issue a fresh moratorium on deepwater oil drilling after district judge Martin Feldman said it would cause irreparable economic harm, but Obama spokesman Robert Gibbs said new moratorium terms from the Interior Department would likely come out "in the next few days."
Obama first imposed the six-month moratorium in late May, after the true extent of the disaster became clear.
He and Vice President Joe Biden, who visited the southern Gulf Coast disaster zone earlier this week, meanwhile met senior officials involved in the clean-up operation in the secure White House Situation Room.
The briefing, Gibbs later said, also covered hurricane projections for the expected stormy summer season and their potential impacts on the response.
Late Wednesday, Obama directed Navy Secretary Ray Mabus, whom he has put in charge of the restoration of the Gulf Coast, to come up with a long-term recovery plan "as soon as possible." On Capitol Hill Thursday, the focus turned again to the bill for clean-up and restoration.
"It will take billions of dollars -- even trillions," Democratic Representative Sheila Jackson Lee told reporters, citing "a presentation by the president's team on the BP oil spill" early in the day.
"We will have an ongoing and unending commitment to fixing this disaster," the lawmaker from Texas said.