for more, we speak to john cummins, who is in vienna. us more about what this latest hurdle is, this of theive progress talks. >> the hurdle is what it has always been which is very much the issue of uranium enrichment. iran says it wants to build around 100 thousand center fugitives, the machines that enrich uranium. them for theeds nuclear program, nuclear energy. u.s. is concerned that iran may use these machines to make fuel for nuclear weapons. sides areow, both trying to jockey for position a little bit. the u.s. is trying to put iranians,n iran and for their part, are trying to do the same thing. it is difficult to sell -- to tell at this stage if it is a serious setback or just a ploy from both sides. >> the goal was to come up with a definitive deal by late july. i am wondering now, with this latest roadblock, if that is going to happen. i assume that is the question everyone is asking this evening. >> it is. these talks were meant to resume in june, but there has been no date set yet. deadline, and the two sides were meant to s