(Video APTN)

Response vessels continued to skim oil out of the waters of the Gulf of Mexico on Monday as crude oil that gushed from a blown-out well burned on the surface, sending plumes of black smoke high into the sky.

Dozens of boats were working on the Gulf and floating hotels have been set up to house the workers who are trying to mop up the crude before it seeps into the marshes on the shoreline.

Bid after bid has failed to stanch what has already become the worst-ever US oil spill, and BP PLC is readying another patchwork attempt as early as Wednesday, this one a cut-and-cap process to put a lid on the leaking wellhead so oil can be siphoned to the surface.

US Coast Guard Petty Officer Larry Chambers, who flew over the oil-fouled waters, said he was upset by what he saw.

"It stops your heart for a moment," Chambers said.

US President Barack Obama planned to meet Tuesday at the White House with the co-chairmen of an independent commission he established to investigate the catastrophic oil spill, said a senior administration official, speaking on condition of anonymity because the meeting had not been formally announced.

Meanwhile, Attorney General Eric Holder planned to visit the Gulf Coast Tuesday to see areas affected by the oil spill and meet with state attorneys general from Louisiana, Alabama and Mississippi and several US prosecutors.

Several US senators have asked the Justice Department to determine whether criminal or civil laws were broken in the spill, which started when a drilling rig exploded on 20 April.

The best-case scenario of sealing the leak is two relief wells being drilled diagonally into the gushing well - tricky business that won't be ready until August.

In the meantime, BP is turning to another risky procedure federal officials acknowledge will likely, at least temporarily, cause 20 percent more oil - at least 100-thousand gallons (380-thousand litres) a day - to add to the gusher.

Using robot submarines, BP plans to cut away the riser pipe this week and place a cap-like containment valve over the blowout preventer.

The crews will eventually cut the leaking riser and place the cap on top of it. The company hopes it will capture the majority of the oil, sending it to the surface.