Wrapping up six days of marathon nuclear talks with mixed results, Iran and six world powers prepared on Tuesday to issue a general statement agreeing to continue negotiations in a new phase aimed at reaching a comprehensive accord by the end of June, officials said.

The joint statement is to be accompanied by additional documents that outline more detailed understandings, allowing the sides to claim enough progress has been made thus far to merit a new round, the officials said.

The talks have already been extended twice as part of more than a decade of diplomatic attempts to curb Teheran's nuclear advance, and the next stage will be presented as a new phase because most of the parties had ruled out another prolongation of this round.