Talks aimed at finalising details of Iran's agreement to suspend key elements of its nuclear programme have hit a stumbling block on the eve of a decisive meeting of the International Atomic Energy Agency.

Foreign ministers from Britain, France and Germany met Kamal Kharrazi, their Iranian counterpart, in the Egyptian resort of Sharm el-Sheikh on Tuesday in an attempt to thrash out details of a resolution to be put to the board meeting of the United Nations nuclear watchdog in Vienna on Wednesday.