China is seen as leading opposition to the United States 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.
Even as PM Narendra Modi was busy getting support from Switzerland, the USA and Mexico, for its bid for membership to the the Nuclear Suppliers Group (NSG), Pakistan was also working overtime to rally support for itself.
Ahead of the meeting here, US Secretary of State John Kerry had written a letter to the NSG member countries, which are not supportive of India's bid, saying they should "agree not to block consensus on Indian admission".
New Delhi has already got the support of major NSG countries, including France, Russia and Britain.
India continues to refuse to sign the nonproliferation treaty, arguing that it is discriminatory since it defines nuclear weapon states as those that tested nuclear devices before January 1967 - which would disqualify India from ever becoming a member.
It is believed that Pakistan has support of China, which has assured that it would not support India's membership until Pakistan was also given the same treatment.
"It's an ongoing process but most countries appear positive", said diplomatic sources as the meeting got underway.
The NSG is a 48-nation club dedicated to curbing nuclear arms proliferation by controlling the export and re-transfer of materials that could foster nuclear weapons development.