TEHRAN (Reuters) - Talks next week between Iran and major powers concerned about its nuclear programme could be the last chance for the West because Tehrans atomic capability is improving, a senior Iranian official was quoted as saying. Ali Asghar Soltanieh, Tehrans nuclear ambassador, raised the stakes for the January 21-22 meeting with the five permanent members of the UN Security Council plus Germany, which want assurances that Iran is not developing nuclear weapons. Once Iran can make its own fuel for a research reactor, which it has said will happen this year, it may not return to negotiations if the talks to be held in Istanbul fail, the official IRNA news agency quoted him as saying on Wednesday. It might be the last chance because by installing fuel rods produced by Iran in the core of the Tehran Research Reactor, probably parliament will not allow the government to negotiate or send its uranium outside the country and the Istanbul meeting might be the last chance for the West to return to talks. Irans Supreme Leader, Ayatollah Ali Khamenei, has the ultimate say on its nuclear policy and diplomacy. Meanwhile, a senior Iranian official and top Chinese diplomats met to discuss Irans nuclear programme on Wednesday, but there was no immediate sign China would accept or decline an invite to tour that countrys nuclear facilities. China has backed UN Security Council resolutions pressing Iran to abandon its disputed nuclear activities but China has close energy and trade ties with Iran and has opposed unilateral sanctions imposed by Europe and the United States. Iranian Deputy Secretary of the Supreme National Security Council Ali Bagheri met with Vice-Foreign Minister Zhang Zhijun and Assistant Foreign Minister Wu Hailong in Beijing, Chinas Foreign Ministry said. Both sides exchanged views on Sino-Iran bilateral relations and the Iran nuclear issue, the ministry said in a brief statement on its website (www.mfa.gov.cn), which also showed pictures of the meetings. It gave no more details. China has yet to say whether it will accept or decline an offer from Iran to tour its nuclear facilities, saying only that it had received the invitation. The European Union has turned down an offer from Iran to tour its nuclear facilities, EU foreign affairs chief Catherine Ashton said on Friday. Ashton said she had consulted Russia and China before deciding that the invitation should not be accepted. The West suspects Irans nuclear programme is directed at developing bombs. Iran says it is for peaceful energy only. Talks next week between Iran and major powers concerned about its nuclear programme could be the last chance for the West, a senior Iranian official was quoted as saying on Wednesday.