BEIJING, June 16 (Xinhua) -- China will send a delegation to attend a new round of high-level nuclear talks between Iran and world powers from Monday to Friday in the Austrian capital of Vienna, a Foreign Ministry spokeswoman said on Monday.

Wang Qun, director-general of the Department of Arms Control of the Foreign Ministry, will head the delegation, Hua Chunying announced at a regular news briefing.

Iran and the P5+1 - China, France, Russia, Britain and the United States, plus Germany - have held four rounds of talks on a comprehensive nuclear accord and are at a crucial stage of beginning drafting, Hua said.

The talks have already entered a "deep-water zone", with more complex and sensitive issues involved, as Iran and the world powers are expected to reach a comprehensive deal before July 20, she said.

Hua called on all the parties to take a flexible and constructive attitude to make joint efforts and accommodate each other's concerns so that the talks can achieve substantial progress.

China will continue to participate in the talks constructively and work with other parties to overcome difficulties to facilitate towards a fair, balanced and mutually beneficial accord, the spokeswoman added.

Western states suspect Iran has been developing atomic weapons under cover of its civilian nuclear plan, while Iran dismisses the allegation, saying its nuclear program is solely peaceful and the allegation is baseless.