(VOVworld) – There is “no guarantee” of a comprehensive agreement on Iran’s nuclear program, said Catherine Ashton, High Representative of the European Union for Foreign Affairs and Security Policyduring her trip to Iran on Sunday. In a joint press briefing with Iranian Foreign Minister Mohammad Javad Zarif, Ashton said there remained a number of difficulties but expressed her optimism in the negotiators’ good will to step up negotiations. Catherine Ashton is optimistic about negotiators’ good will. (Photo: Reuters) Zarif said Iran has laid out all its conditions and stayed ready to clinch a final deal. He was confident that a deal could be reached between Iran and the P5+1 by the end of July, adding that this historic document must respect the rights and interests of the Iranians.