His remarks came after a meeting with the governors of Louisiana, Florida and Alabama, along with other officials involved in the spill response operations.

BP's obligations

Obama warned BP not to short-change local communities who have lost their livelihoods, saying the London-based energy giant must be clear about its "moral and legal obligations … for the damage that has been done".

in depth

"What I don't wanna hear is when they're spending that kind of money on their shareholders and spending that kind of money on TV advertising, that they're nickel-and-diming fishermen or small businesses here in the Gulf who are having a hard time," he said.

Obama's visit to the region came as engineers worked to settle a funnel-like cap over the deep-sea leak to try to collect some of the oil now spreading across the coastline of four states.

"What I don't wanna hear is when [BP is]spending that kind of money on shareholders and TV advertising, that they're nickel-and-dimming fishermen or small businesses here in the Gulf who are having a hard time"

Barack Obama, US president

On Friday BP used the "cut and cap" method to begin siphoning off oil from its broken pipe and funnelling it onto a ship.

A device resembling an upside-down funnel was lowered over the blown-out well but crude continued to escape into the Gulf through vents designed to prevent ice crystals from clogging the cap.

Engineers hoped to close several vents throughout the day.

"Progress is being made, but we need to caution against over-optimism,'' Coast Guard Admiral Thad Allen, the government's point man for the crisis, said.

Early in the day, he said the cap was collecting an estimated 158,000 litres a day, less than one-tenth of the amount leaking from the well.

The operation follows a series of unsuccessful attempts to cap or contain the gushing leak since an explosion on April 20 tore through the BP-leased Deepwater Horizon rig just off the Louisiana coast.

Spreading disaster

The BP-leased Deepwater Horizon oil rig exploded on April 20 and has since caused a massive, ongoing spill said to be the worst in US history.

Tar balls started to wash up on Florida beaches, threatening its tourism-based economy [EPA]

Eleven workers were killed in the blast.

On Thursday the Obama administration handed BP a $69m bill for recovery costs to date, a figure that is likely to grow in the weeks and months ahead.

BP has already spent well over $1bn on its response to the spill and has attempted to reassure investors that the firm is not at threat of insolvency due to the spill.

The US government estimates about 12,000 to 19,000 barrels of crude is currently gushing out daily from the ruptured wellhead some 1.6km under the sea, and that between 83 million and 178 million litres have already been spilled since the rig's collapse.

Meanwhile oil has reportedly reached the shores of the four Gulf states, turning its marshlands into death zones for wildlife and staining its beaches rust and crimson in an affliction.

Some said the scene brought to mind the plagues and punishments of the Bible.

"In Revelations it says the water will turn to blood," said PJ Hahn, the director of coastal zone management for Louisiana's Plaquemines Parish.

"That's what it looks like out here, like the Gulf is bleeding. This is going to choke the life out of everything… It makes me want to cry."