BP could begin sealing its oil well in the Gulf of Mexico on Monday - three months after its rupture led to the worst oil spill in United States history.
The official overseeing the federal response says engineers are preparing to pump mud and cement into the well in a procedure known as a "static kill", the BBC reports.
Admiral Thad Allen says mud and cement would then be pumped in from a relief well below five to seven days and only that proceduere would fully seal it.
The well has been temporarily sealed for two weeks after spilling many millions of litres of oil each day into the sea since 20 April.
The explosion on a drilling rig off Louisiana that triggered the leak killed 11 workers.
Last week, BP reported a record $US17 billion loss, having set aside $US32 billion to cover the costs of the spill.