NEW DELHI : Quiet but intense diplomacy is on to shore up support for India ’s membership of the Nuclear Suppliers Group (NSG).NSG’s plenary session is slated for June 23-24, in Seoul. The group functions as a closed club that restricts access to nuclear hi-tech. Ranking diplomats such as Foreign Secretary S Jaishankar and Secretary (West) in the Ministry of External Affairs, Sujata Mehta, are spearheading India’s diplomatic outreach, visiting key foreign capitals and explaining New Delhi’s case.ET spoke to senior diplomats familiar with these high-level engagements. They spoke on the condition of anonymity. China has argued against India’s entry while the US has backed it. The US on Friday again urged the 48-member NSG to back India. South Korea , which will chair NSG now and host the meeting, is a key country. Diplomats say Seoul is playing a big role in spreading the word for India. Jaishankar had paid a quiet visit to Seoul just before the prime minister’s trip to the US. And top South Korean and Indian officials are in discussions over the best way to fashion an argument for India.Discussions are also on with past and current heads of NSG, respectively, Czech Republic and Argentina.Both favour India’s entry. China has been leading the group of countries — including Austria Ireland , South Africa, Turkey and New Zealand — blocking India’s entry into the coveted club.This group wants a debate on the process within NSG to include new members that are not signatories to the Nuclear Non-proliferation Treaty. New Zealand, which has now softened its stand, had initially demanded a twopronged approach for the entry of new members, informed sources told ET.First, it wanted a debate within NSG on the process of expansion. Second, it wanted a specific discussion on India’s application.It is learnt the White House will play a key role in securing New Zealand’s support. Meanwhile, a close Indian partner among NSG members has expressed optimism in securing Austria’s backing.The India-South Korea agreement on New Delhi’s entry is based substantive grounds, diplomats said. The two signed a civil nuclear pact in 2011. Seoul is also looking to enter the emerging Indian nuclear energy market.South Korean entities will supply components for six nuclear reactors that US-based Westinghouse is setting up in Andhra Pradesh.Also, Seoul will be partly financing the Westinghouse project. Senior diplomats told ET that US EXIM Bank, lead financier for the Westinghouse project, will approach South Korean funds for support.This apart, diplomats said, Seoul-New Delhi relations are also informed by South Korean companies’ big investments in India. Last year, a South Korea cell was opened in the Department of Industrial Policy & Promotion.MEA’s Secretary (West) Mehta was tasked with visiting European capitals not yet on board. Her brief, diplomats said, was to present India’s case to European countries such as Austria and Ireland that are opposed to New Delhi’s entry into NSG, as they were in 2008 when the country received a clean waiver from NSG on nuclear commerce.Mehta looks after India’s relations with the EU and European countries barring France and Britain, which fall under the foreign