Justice Department spokesman Wyn Hornbuckle said the government was pursuing a gross negligence charge against BP in a case that starts this week in New Orleans.
"We intend to prove that BP was grossly negligent and that the company engaged in willful misconduct in causing this disastrous oil spill," he told Bloomberg News.
"We are seeking civil penalties and a judgment that BP and others are liable without limitation for removal costs and natural resource damages -- exposure that could amount to billions of dollars."
BP General Counsel Rupert Bondy said last week the company was ready for the trial in the U.S. District Court for the Eastern District of Louisiana.
A two-phase trial will determine responsibility for the Deepwater Horizon disaster and the amount of fines for alleged violations of the Clean Water Act. Eleven rig workers died April 20, 2010, when the Deepwater Horizon rig exploded and sank, leading to the industry's worst offshore oil spill.
The district court last month accepted a guilty plea from BP that resolves "all federal criminal charges" against the company for the 2010 oil spill in the Gulf of Mexico. BP in November agreed to plead guilty to 14 criminal charges stemming from the accident as well as to $4 billion in fines and penalties.