Iran's security chief Mohsen Rezaei has told the visiting Pakistani army chief Asim Munir that Tehran would not allow nuclear material to leave the country, according to state TV.
"Not even a tiny bit of enriched nuclear material will leave Iran; such materials constitute a major asset and national wealth for the Iranian people, intended for use within the country," said Rezaei, Iran's secretary of the Supreme National Security Council on Tuesday.
"There will be no negotiations until America takes steps to build trust, a process that must begin with the fulfilment of Iran's conditions," he added.
Iran's chief negotiator and parliament speaker Mohammad Bagher Ghalibaf made similar remarks to Munir, who is in Tehran as part of a renewed push to mediate a peace deal between Iran and the United States.
"We have nothing new to say; America cannot gain Iran's trust unless it fulfils the seven conditions," said Ghalibaf, noting that "threats and military manoeuvres cannot influence Iran's strategic decisions".
Iran has demanded, among other things, a ceasefire across the Middle East, the unfreezing of its assets abroad and the lifting of sanctions on its oil sector.
Earlier, Iran's President Masoud Pezeshkian discussed mediation efforts and regional developments during a meeting with Munir in Tehran, Iran's Nournews reported.
The war was sparked in late February by the United States and Israel when they launched a wave of deadly attacks on Iran.
The warring parties agreed to a memorandum of understanding mediated by Pakistan in June that was expected to create a framework for a permanent resolution to the conflict, but the deal did not last long.
Negotiations have effectively been at an impasse since then, and recent indirect talks between the US and Iran on the sidelines of the UN General Assembly failed to produce a breakthrough.
Qatar, which has also been involved in the negotiations between Iran and the US, said the talks remain ongoing, with both sides continuing to engage.
Tehran had previously maintained it would not hand over its nuclear materials, enriched to 60 percent, close to the atomic bomb threshold of 90 percent, to any country but had hinted at the possibility of diluting them within Iran's borders.
Washington and its allies have imposed waves of sanctions on Iran, accusing it of seeking to build nuclear weapons, a charge Tehran has long denied.
