BEIJING, April 13 (Xinhua) -- Cui Tiankai, assistant to Chinese Foreign Minister, will visit Iran and Russia from April 14 to 18, Chinese Foreign Ministry spokesman Liu Jianchao said here Thursday.

    "Cui will exchange views with Iranian and Russian diplomats on Iranian nuclear issue and other issues of common concern," Liu told a regular news conference.

    Iranian President Mahmoud Ahmadinejad announced on Tuesday that Iran had successfully enriched uranium.

    "Cui's visit aims at stepping up the exchanges with all parties concerned in a bid to help resolve the Iranian nuclear issue properly," Liu said.

    "China is concerned about the statement by the Iranian side and is worried about the way in which things are developing," Liu said.

    China appeals to the parties concerned to show restraint and not take actions that might further aggravate the situation, he said, adding the issue should be properly settled through negotiations and diplomatic efforts. Enditem