The United States has said it would oppose a proposed nuclear deal between China and Pakistan as it requires a specific exemption from the Nuclear Suppliers Group (NSG) like the US deal with India. "This appears to extend beyond cooperation that was grandfathered when China was approved for membership" state department spokesman P. J. Crowley told reporters Tuesday when asked on what grounds it would oppose the deal when it had opened the door to such agreements with the US-India deal. "We believe that such cooperation would require a specific exemption approved by consensus of the Nuclear Suppliers Group, as was done for India. So we're not looking at any difference between the two," he said adding the US had "asked China to clarify the details of its sale of additional nuclear reactors to Pakistan. The US has served notice that it would object to the deal at a meeting next week of the 46 nation group that regulates nuclear trade and its rules forbid sales of nuclear technology to such countries that have not signed the Nuclear Non-Proliferation Treaty (NPT). China has maintained that its agreement with Pakistan to supply two additional nuclear reactors pre-dates its joining the NSG in 2004 and therefore does not need its approval. Asked if China had informed the US about the sale of two nuclear reactors to Pakistan, Crowley said: "This was an issue that we've had periodic discussions with China for some time."