LONDON — BP said today that its partners in the leaking Gulf of Mexico oil well must share responsibility for the costs in dealing with the disaster, on which BP said it has now spent $2 billion.

BP hit back at Anadarko Petroleum, which has a 25 percent stake in the gushing well, following Anadarko's statement on Friday accusing BP of gross negligence in operating the drilling rig.

Anadarko said the joint operating agreement makes BP responsible to co-owners for any damage due to gross negligence or willful misconduct.

In a statement today to the London Stock Exchange, BP countered that all the partners shared in liability for damage resulting from exploration in Mississippi Canyon Block 252.

"All the co-owners of the leasehold interest previously entered into a written operating agreement under which ... the parties would share the costs of operations, including the cost to clean up any spill resulting from drilling the MC252 exploratory well, according to their respective ownership interests," BP said.