A senior Iranian negotiator underlined the complexity of the fourth round of talks between Tehran and the six major world powers, but meantime, stressed that both sides were on the right path to narrow down their differences to reach a permanent deal. Seyed Abbas Araqchi, who is also the Iranian Deputy Foreign Minister for legal and international affairs, said in an interview with state tv on Saturday that the Vienna negotiations were “tough” but they were on the right path. He further added that Iran’s Arak reactor will remain a heavy water facility. The Iranian official underlined that Tehran’s red line in the nuclear talks with the Sextet of world powers is the rights of the Iranian nation. He further laid emphasis on the country’s enrichment right and said that the (Arak) reactor would continue its work with 40 megawatts of power. An informed Iranian source said on Saturday that the next round of negotiations between Iran and the Group 5+1 (the five permanent UN Security Council members plus Germany) may be held in mid-June. “Iran and the G5+1 have held initial discussions about the mentioned date, namely June 16 to 19, but the date for the next round of talks has not been set yet,” an Iranian official who spoke on condition of anonymity said. Meanwhile Russian sources have also reported that the next round of talks will be held on the mentioned date at the level of political director-generals. Iran and the Sextet of powers wrapped up their fourth round of talks in Vienna on Friday. Iran says there has been no tangible progress in writing the draft text of a comprehensive agreement over the country’s nuclear energy program. "We will have one or two more rounds of talks in June. Talks will continue," Araqchi said at a news conference on Friday after the end of the talks. On Friday, an official close to the Iranian nuclear negotiating team criticized the West for pursuing unreasonable and “excessive demands” during the talks. Iran and the six countries have been discussing ways to iron out differences and start drafting a final deal that would end the West’s dispute with Iran over the country’s nuclear energy program. In November 2013, the two sides signed an interim nuclear deal in the Swiss city of Geneva that came into force on January 20.