to trade with other countries in the civilian nuclear field.
Ratification is a key step towards separating India's civilian and military nuclear operations, and could help unlock tens of billions of dollars in U.S.-led investment in new nuclear generation capacity.
Yet as recently as a year ago, talks on India joining the group were being slowed by the prospect that its accession might trigger similar demands by other countries that have not signed the NPT, such as Pakistan, to join.
"India sees its ratification of its Additional Protocol as an arrow in its quiver supporting its quest for NSG membership," said Mark Hibbs, a nuclear expert at U.S. think-tank the Carnegie Endowment.
But the lack of verification of India's weapons programme, which contrasts with tighter controls on NPT signatories, would continue to be a concern.
"India's entire nuclear weapons programme is totally outside the scope of its Additional Protocol," Hibbs added. "It isn't clear to most people what the utility of the Additional Protocol in India is as a verification instrument."