Gulf of Mexico oil spill has cost $350 million so far: BP

British energy giant BP today said the massive Gulf of Mexico oil spill had so far cost it $350 million.

"The cost to date of the response amounts to about 350 million dollars, including the cost of spill response, containment, relief well drilling, commitments to the Gulf Coast States, settlements and federal costs," BP said in a statement.

The company, at loss as to what to try next after an approach aimed at capping a gushing leak with a containment dome came to a nought is faced with the grim prospect of the crisis spiralling into a major environmental calamity.

The White House was also working hard at damage control to limit the fallout from the massive disaster that might jeopardise president Obama's political and energy agenda.

After their failure to collect and funnel the oil leak with a 100-ton containment box, BP officials on Sunday were considering using a smaller container that might be less prone to clogging.

With a smaller box to cap the leak the oil and seawater mixture inside the container would be warm enough to prevent formation of a slush that had clogged the larger container, according to geochemist David Valentine of UC Santa Barbara. Gas and cold water mix near the sea floor can form a crystal like matrix.