The West must take concrete confidence-building steps in its nuclear negotiations with Iran, a senior Islamic republic official preparing the next round of talks said Friday, after returning from discussions with China and Russia. Ali Baqeri, the deputy to Iran's chief nuclear negotiator Saeed Jalili, called on "the West to take concrete steps to build trust with the Iranian people," Iranian news agencies reported. That appeared to echo more explicit demands from Tehran in recent days that the West ease its economic sanctions hitting Iran's oil and finance sectors. Baqeri said he held "serious discussions" in Beijing and Moscow about the talks between Iran and the P5+1 group comprising the five permanent UN Security Council members plus Germany. The two sides last month renewed dialogue in Istanbul that had been in limbo for the previous 15 months. Another round of talks is scheduled for May 23 in Baghdad. Baqeri stressed the "importance of the P5+1 countries' commitments concerning Iran's nuclear rights in the framework of the NPT (the nuclear Non-Proliferation Treaty) in line with both sides' agreement in the Istanbul talks." He also noted that both sides aim to move forward on "the basis of a step-by-step approach and reciprocity," and said the outline of that process "will be determined before the Baghdad meeting." The "step-by-step" formulation relies on each side offering matching compromises at around the same time in an effort to build up trust that has been sorely depleted over past years. Baqeri's mention of an "agreement" in Istanbul appeared to refer to a mutual understanding, voiced by EU chief policy official Catherine Ashton, that the NPT formed the basis for "a sustained process of serious dialogue." That would "ensure all the obligations under the NPT are met by Iran while fully respecting Iran’s right to the peaceful use of nuclear energy," Ashton said after the Istanbul talks. Although several UN resolutions against Iran demand the Islamic republic suspend all uranium enrichment, there have been hints that the United States could be willing to accept Tehran enriching uranium up to five percent, needed for nuclear energy production. The question of Iran enriching uranium to 20 percent -- as it is currently doing, ostensibly to make medical isotopes -- is seen by Western powers as a key point of the negotiations. Uranium has to be enriched to 90 percent or above to be used to make atomic warheads. Other issues include Iran's enrichment activities in a near-impregnable nuclear bunker in Fordo, and the International Atomic Energy Agency being able to conduct more invasive inspections. For Iran, the focus is on having its enrichment activities recognised and seeing Western economic sanctions and UN sanctions lifted.