Three employees of BP have pleaded not guilty to criminal charges linked to the Deepwater Horizon disaster in 2010.
Eleven workers were killed when a rig exploded in the Gulf of Mexico.
Well-site bosses Robert Kaluza and Donald Vidrine have been charged with manslaughter.
Meanwhile, the United States government has banned BP from new federal contracts because of what Washington says is a lack of business integrity following the disaster.
The EPA said the suspension was due to BP's "lack of business integrity" over its handling of the 2010 Deepwater Horizon disaster in the Gulf of Mexico.
But both BP and the agency said the temporary ban would not affect existing agreements held with the US government.
Since the Deepwater Horizon disaster in 2010, the USA has granted BP more than 50 new leases in the Gulf of Mexico.
BP has pleaded guilty to 14 criminal charges and was fined $US4.5 billion on 15 November by the US Department of Justice.
The 2010 Deepwater Horizon disaster killed 11 workers and released millions of barrels of crude into the Gulf of Mexico over 87 days.
