TEHRAN – Iran's top decision-maker Ayatollah Ali Khamenei said on Wednesday he will not allow any “retreat” on Tehran's nuclear rights, ahead of a new round of talks with world powers. While expressing support for negotiators engaging in nuclear talks in Geneva today, the supreme leader said the Iranian team was instructed to respect Tehran's “red lines.” He appeared to be referring to Iran's insistence on continuing to enrich uranium on its own soil, a process that can create medical isotopes and fuel for power plants, but at much higher levels can also be used to generate a key component for an atomic bomb. “I insist on stabilizing the rights of the Iranian nation, including the nuclear rights,” Khamenei told militiamen of the Basij force in Tehran, in a rare, live televised address. “I insist on not retreating one step from the rights of the Iranian nation,” he added. The remarks come as the so-called P5+1 group of world powers — the United States, Britain, France, China and Russia plus Germany — seek an elusive deal with Iran to curb its controversial nuclear activities. The P5+1 representatives and Iranian negotiators, led by Foreign Minister Mohammad Javad Zarif, meet for the third time in a little over a month in the Swiss city on Wednesday. World powers suspect Iran is masking military objectives in its nuclear work, despite repeated denials in Tehran and officials insisting the nuclear program is for purely peaceful purposes. Final decisions on the program rest with Khamenei. “I am not interfering in the details of these negotiations but there are red lines and limits that must be respected,” Khamenei said. “I have told the officials that they must respect these limits, and not fret about the hullabaloo of the enemies and those opposed” to these talks, he said without elaborating. Meanwhile, President Hassan Rohani in a telephone call with British Prime Minister David Cameron stressed Tehran's firm right to pursue a peaceful nuclear program, Iranian media reported Wednesday. Cameron's call on Tuesday to Rohani, the first such high-level exchange in a decade, came on the eve of a new round of talks in Geneva between world powers and Iran on Tehran's nuclear program. “As Iran is determined that its nuclear activities will remain peaceful, it will strongly defend its nuclear rights,” the official IRNA news agency reported Rohani as telling Cameron. “We will accept no discrimination on this issue. The language of respect must replace that of threats and sanctions,” he added. Downing Street confirmed that Cameron and Rohani had discussed the talks between world powers and Iran on Tehran's nuclear program, the next round of which starts in Geneva on Wednesday. Cameron “underlined the necessity of Iran comprehensively addressing the concerns of the international community about their nuclear program, including the need for greater transparency,” a Downing Street statement said. IRNA said Rohani also held talks on the telephone with Chinese President Xi Jinping, telling him Tehran was seeking “an accord which preserves its rights and shows that the Iranian nuclear program is totally peaceful.” He called for China to oppose “excessive demands of certain countries,” referring to France which took a tough stand at the last round of talks in Geneva at the start of November. Parliament speaker Ali Larijani, meanwhile, insisted in a speech to MPs that the Islamic republic would fully defend “its nuclear rights” in Geneva. And before leaving Rome for Geneva, Iranian Foreign Minister Mohammad Javad Zarif told reporters that a deal “depends to what degree (world powers) are ready to respect Iran's rights.” – Agencies