US Interior Secretary Ken Salazar has told a senate panel that a six-month moratorium on deepwater drilling will stay in place until safety is assured.
But he sought to reassure senators that the moratorium - imposed after the huge Gulf of Mexico spill - was a "pause" rather a permanent halt to exploration.
Coast Guard Adm Thad Allen said the amount of oil captured from the leaking well could almost double by next week.
President Barack Obama has criticised BP's efforts to deal with the spill.
He is due to make his fourth trip to the Gulf of Mexico next week.
Mr Salazar's announcement came a day after he announced plans to bolster safety requirements for shallow-water oil drilling.
He said that drilling would continue, but it "has to be done in a safe way".
Mr Salazar said the pause, which was put in place following the 20 April explosion of the Deepwater Horizon rig, would remain "until we can have a sense of safety, until we have a sense that this can never happen again".
Mr Salazar also told the panel he would ask BP to repay the salaries of any workers laid off due to the six-month moratorium.
Three committees and two subcommittees on Capitol Hill were to discuss matters related to the oil spill and oil industry on Wednesday.
Among the new safety regulations announced by Mr Salazar on Tuesday, oil companies drilling in US waters will now have to inspect their blow-out preventers and provide safely certificates.
The failure of the blow-out preventer on the Deepwater Horizon rig led to the oil spill, the worst in US history.
A containment cap placed on the blown-out well last week is now helping to contain some of the leaking oil.
Adm Allen said in a press conference on Wednesday that the containment operation was now catching up to 630,000 gallons (2,864,037 litres) daily.
He said he hoped the existing containment structure would soon be able to hold 1.17 million gallons per day.
"We're only at 15 [15,000 barrels] now and we'll be at 28 [28,000 barrels] next week. We're building capacity," said Adm Allen.
At some point there might "have to be a transition between a containment cap and a regular cap", he said.
Adm Allen added that Obama administration officials were talking to BP about a longer-term containment strategy with "built-in redundancies".
The government has estimated that 600,000 to 1.2 million gallons a day are leaking from the bottom of the sea.
BP has said it will donate net revenues from the oil recovered to a fund to restore wildlife habitats on the coastlines of four affected Gulf Coast states.
However, a BP spokesman told the AP news agency that it could not say how much of the recovered oil had been processed.
Adm Thad Allen wrote to BP on Tuesday demanding "more detail and openness" about how the company is managing claims for compensation payments to individuals and businesses in the region.
"The BP Deepwater Horizon oil spill is having a devastating impact on the environment and the economy of the Gulf Coast states and their communities," he wrote.
Meanwhile, tests have shown that underwater oil plumes have travelled at least 64km (40 miles) from the leaking well, the US government says.
Scientists noted that concentrations of oil in the plumes were "very low", but said the plumes were very difficult to clean up, and they could damage the Gulf's abundant sea life by depleting oxygen in the water.
Speaking on US network NBC's Today show on Wednesday, BP spokesman Doug Suttles maintained BP's position that no massive underwater oil plumes in "large concentrations" had been detected.
"It may be down to how you define what a plume is here," he said.
Oil has been leaking into the Gulf of Mexico since the Deepwater Horizon rig exploded and sank off the coast of the US state of Louisiana, killing 11 workers.
The morning the rig exploded, a BP executive and an official from Transocean, which operated the rig, argued over how to proceed with the drilling, survivors of the blast told CNN.
The workers said BP had routinely cut corners and pushed ahead despite concerns about safety.
A BP spokesman said it would not comment on specific allegations until an investigation into the accident was completed, but said that "BP's priority is always safety".
BP chief Tony Hayward is scheduled to appear before Congress next week.
BP shares fell 3.4% on Wednesday over worries that the company will have to suspend its dividend payments to pay for legal claims and cleaning up the spill.