BP says the oil spill in the Gulf of Mexico has cost it $450m (£308m) so far, an increase of $100m (£68m) on the figure reported earlier this week.

President Obama is pushing for a law that could force the oil company to pay the full cost of the clean-up operation.

At least four million gallons have leaked from the well that was damaged in an explosion more than three weeks ago.

John Moylan reports.