National Incident Commander Thad Allen told reporters Friday it is too early to declare victory.
"We should not be writing any obituary for this event until the well is completely sealed, until we have no more oil on the surface of the water, until we understand where all the oil has gone to, until the beaches are cleaned, until the local -- federal, state and local officials agree that the beaches are clean," he said at a news briefing at Tyndall Air Force base in Florida.
Debris was being cleared out from the relief well Friday, Allen said. He said a final casing line would be run out Saturday or Sunday, with "hydrostatic top kill" beginning 24 to 36 hours later.
"We are going to make sure this well is killed, make sure the oil on the surface is responded to, and make sure the shores are clean -- and how clean is clean is something we will develop with our local leaders and the trustees of all of the resources that are applied as we move forward," he said.