China said on Sunday that more talks were needed to build a consensus on which countries can join the main group controlling access to sensitive nuclear technology, after a push by the United States to include India.
China is seen as leading opposition to the U.S. move to include India in the 48-nation Nuclear Suppliers Group (NSG), but other countries, including New Zealand, Turkey, South Africa and Austria also oppose Indian membership, according to diplomats.
The NSG aims to prevent the proliferation of nuclear weapons by restricting the sale of items that can be used to make those arms.
India already enjoys most of the benefits of membership under a 2008 exemption to NSG rules granted to support its nuclear cooperation deal with Washington, even though India has developed atomic weapons and never signed the nuclear Non-Proliferation Treaty (NPT), the main global arms control pact.
"Large differences" remain over the issue of non-NPT countries joining the NSG, Chinese Foreign Ministry spokesman Hong Lei said in an online statement.
"With regard to what to do on the issue of non-NPT signatories joining (the NSG), China consistently supports having ample discussion on this to seek consensus and agreement and come to a unanimous decision," Hong said.
"The NPT is the political and legal basis for the entire international non-proliferation system," Hong said, adding that China would support the group in further talks to come to a consensus at an early date.
Opponents argue that granting India membership would further undermine efforts to prevent proliferation. It would also infuriate India's rival Pakistan, which responded to India's membership bid with one of its own and has the backing of its close ally China.
Pakistan joining would be unacceptable to many, given its track record. The scientist that headed its nuclear weapons program ran an illicit network for years that sold nuclear secrets to countries including North Korea and Iran.
A decision on Indian membership is not expected before an NSG plenary meeting in Seoul on June 20, but diplomats have said Washington has been pressuring hold-outs.
Most of the hold-outs oppose the idea of admitting a non-NPT state such as India and argue that if it is to be admitted, it should be under criteria that apply equally to all states rather than under a "tailor-made" solution for a U.S. ally.