China hopes to see the six major countries (P5+1) that used to engage in Iran nuclear talks start \"sustained dialogues\" at an early date, said the Chinese envoy to the International Atomic Energy Agency (IAEA). \"Thanks to the joint efforts of the parties concerned, the process of dialogue and negotiation on the Iranian nuclear issue is showing positive momentum,\" said Cheng Jingye, China\'s permanent representative and ambassador to the United Nations and other international organizations in Vienna. \"The P5+1 and Iran have both expressed readiness and begun preparations for serious dialogue. This is significant for moving toward a diplomatic solution of the Iranian nuclear issue,\" Xinhua news quoted Cheng as saying while addressing a quarterly board meeting of the IAEA. He also said, \"We hope to see the P5+1 and Iran start a process of sustained dialogue at an early date, build up mutual trust based on the principle of step by step and reciprocity and search for a comprehensive and long-term proper solution to the Iranian nuclear issue.\"