Washington, Nov 22 (IANS): Saying it was still studying India's regulations on civil nuclear liability, the United States has asserted that for it ensuring a level playing field for American companies in India remained a priority.

"Completing the US-Indian civil nuclear cooperation partnership is central to both our nations' long-term prosperity and India's future energy security," the State Department said Monday in response to a question on the proposed regulations for civil nuclear liability in India.

"Ensuring a level playing field for US companies to invest in India's civil nuclear industry remains a priority for the State Department," it said in a statement. "We are continuing to study India's regulations on civil nuclear liability."

Last week Prime Minister Manmohan Singh had told US President Barack Obama in Bali that specific US grievances on the civil nuclear liability law could only be addressed within "four corners of the law of the land".

The rules notified by India relating to Civil Liability for Nuclear Damage Act provide the nuclear plant operator the right to recourse for the period for which the supplier of equipment has taken liability for patent or latent defects or sub-standard services under a contract.

According to the rules, an operator's claim will in no case exceed the actual amount of compensation paid by him up to the date of filing such claim.

The US has told India that its civil nuclear liability law will have to be harmonised with international conventions and the current regime imposed a heavy burden on the operators of nuclear plants in India.