The White House sent BP a bill for $51 million, the third sent to the British energy giant and its partners for government expenses incurred in efforts to halt the oil spill under a US law requiring oil firms to pay for cleanups.

Two earlier bills to BP and other responsible parties this month amounting to $70.89 million dollars have been paid in full.

BP also said it has spent two billion dollars so far on cleaning up the spill and compensating residents and businesses facing ruin nine weeks into the nation's worst ever environmental disaster.

Some 32 US firms, whose operations have been left idle in the area since US President Barack Obama imposed a moratorium on deepwater drilling in the Gulf, were urging federal judge Martin Feldman to ease the restrictions.

But government lawyer Guillermo Montero replied that deepwater drilling was more complicated than many other industries and the government had to review and, if necessary, update its safety protocols.

AFP