EU foreign policy chief Catherine Ashton has urged the P5 + 1 group of world powers to be " determined and creative " in the upcoming talks with Iran.Ashton said on Saturday that the P5+1 (Britain, China, France, Russia, and the United States plus Germany) should take more measures in order to build a level of "communication" and "trust" with Iran. "When I first started to lead these negotiations, we weren't really discussing the subject. Now we discuss the subject in detail, we have the slideshow presentations, we have a real discussion about the issues both when the technical-level discussions take place and the political-level," Ashton said. The latest round of talks between Iran and the P5+1 was held in Almaty, Kazakhstan, on February 26-27. The two sides agreed to convene again in the city on April 5-6 to continue talks after holding expert-level talks in the Turkish city of Istanbul on March 17-18. A delegation of Iranian experts will leave Tehran for Istanbul later on Sunday to attend the expert-level meeting. Both sides have expressed hope and optimism about the future of the talks. On February 28, Reuters quoted an unnamed Western diplomat as saying that the Almaty meeting had been “more constructive and more positive than previous meetings because they were really focusing on the proposal on the table.” In an interview with Austrian broadcaster ORF on March 1, Iran’s Foreign Minister Ali Akbar Salehi also described the latest round of the talks as a “milestone” and a “turning point in the negotiations.” The United States, Israel and some of their allies have repeatedly accused Iran of pursuing non-civilian objectives in its nuclear energy program, with United States and EU using this pretext to impose several rounds of illegal unilateral sanctions against Tehran. Tehran refutes the allegation, maintaining that as a signatory to the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) and a member of the International Atomic Energy Agency (IAEA), it has the right to enrich uranium for peaceful purposes.