A minority partner in the BP oil well that ruptured in the Gulf of Mexico almost two months ago accused BP of "reckless" decisions leading to the disaster.
Anadarko Petroleum, which has a 25 percent stake in the well, slammed BP for its management of the operation off the coast of Louisiana.
Hackett's statement adds pressure to BP as lawmakers and regulators have focused squarely on how well-managed its drilling operations were in the Gulf leading up to the massive spill.
Anadarko owns 25 percent of the drilling operation, and could face partial liability for the operations that led to the accident. Other companies have also found their role in the spill scrutinized, such as Transocean and Halliburton, both of which provided certain services onboard the rig.
The rating agency Moody's shifted its rating of Anadarko on Friday to "junk" status, attributed to the uncertainty in the costs the company might face for its role in the Gulf of Mexico oil spill.
Hackett's remarks were also as much of a PR move on behalf on Anadarko as they could be as well, with the chairman warning that it might act to "protect its rights relative to BP's performance as operator" in proceedings to determine liability in the incidence.
"We recognize that ultimately we have obligations under Federal law related to the oil spill, but will look to BP to continue to pay all legitimate claims as they have repeatedly stated that they will do," said Hackett.