Here are 10 developments in the story:
The NSG meeting in Seoul "is only to deliberate on the entry of members who signed the NPT (nuclear Non-Proliferation Treaty)," Chinese Foreign Ministry spokesperson Hua Chunying said, adding, "The entry of non-NPT countries was never on the meeting agenda."
The official also said: "China will play a constructive role in the discussions, although parties are yet to see eye-to-eye on this issue, such discussions help them better understand each other."
Hours later, France said in a statement that India's inclusion in the NSG - which controls access to nuclear technology - will bolster global efforts against proliferation.
China's statements came as Mr Jaishankar rushed to Seoul to push India's bid as it goes down to the wire. He was earlier supposed to fly with Prime Minister Narendra Modi to Tashkent for a multilateral meet.
PM Modi is expected to meet President Xi on Thursday on the sidelines of the event in what the government sees as the last chance to persuade Beijing to come around.
Indicating that India faces a tough fight, foreign ministry sources told NDTV: "The NSG process is delicate and complex. Don't speculate on the outcome."
China is seen as the leading opposition to US-backed moves to include India in the NSG. Turkey, South Africa, Ireland and New Zealand are also against it.
China has also backed Pakistan, which responded to India's membership bid with one of its own.
India had cited France as a precedent for the inclusion of a nation which was not a signatory to the NPT. France signed the NPT in 1992. China, however, pointed out that France is a founder member of the NSG.
The NSG works on unanimity and even one "no" vote can scuttle India's bid for inclusion in the group that aims to prevent the proliferation of nuclear arms by restricting the sale of items that can be used in making them.
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