Iran will unveil a new advance in its nuclear program in the coming months, the head of its Atomic Energy Organisation was quoted as saying on Saturday, in comments that showed defiance in the face of new UN sanctions. “In the next few months Iran will announce a new nuclear achievement in connection to the production of fuel for its Tehran research reactor,” Ali Akbar Salehi was quoted as saying in the Resalat daily. He gave no details. The last major advance Iran announced was in February, when it said it had started refining uranium to 20 percent purity -- saying it wanted to produce fuel for the Tehran reactor, which makes isotopes for treating cancer. That increased Western concerns as it meant Iran was now refining uranium closer to the level needed for nuclear weapons, adding to the momentum behind a fourth round of sanctions passed by the UN Security Council Wednesday. The International Atomic Energy Agency (IAEA) says there are reasons to suspect Iran is actively pursuing nuclear weapons capability. Once 20 percent purity is reached, the next step to the 90 percent needed for a warhead is much less onerous. Iran called Western powers Saturday to accept a nuclear fuel swap deal brokered by Turkey and Brazil as a “dignified” way out of an intensified atomic standoff, the state news agency IRNA reported. “The best dignified way out of Iran's nuclear issue for Western countries is to accept the fuel swap,” the head of Iran's Atomic Energy Organisation, Ali Akbar Salehi, told IRNA. He branded the standoff with world powers over Iran's atomic programme as their “self-created quagmire.” In May, Iran signed a deal with temporary UN Security Council members Turkey and Brazil to ship about half of its low enriched uranium (LEU) stockpile to Turkey for an exchange with higher enriched reactor fuel. Western powers reacted coolly to the deal, which builds on an October proposal by the UN nuclear watchdog to ship Iran's LEU to Russia and France to be converted to reactor fuel. But Iran dragged its feet for several months, insisting it wants a simultaneous swap on its own territory, a condition that was rejected by world powers backing the UN