Iran will be presented with a stark choice of either abandoning its nuclear ambitions or facing increased isolation in the international community when it meets with the world's major powers, the US State Department said Monday, according to dpa. The US reaction came after it was announced that Iran will meet with officials from the five UN Security Council members - the US, China, Russia, Britain and France - plus Germany on October 1 to discuss its disputed nuclear programme. It will be the first such meeting between Iranian officials and the six countries since July 2008. State Department spokesman Ian Kelly said the nuclear issue would be "front-and-center" in the talks, despite Iran's insistence that it considers the matter closed. "We plan to address this issue of (Iran) not living up to their obligation head on," Kelly told reporters in Washington. The US delegation would be led by William Burns, the State Department's undersecretary for political affairs. "We hope that the six (countries) can really lay out in a very stark fashion the choices they have, and we're going to take this opportunity to do that," Kelly said. US Energy Secretary Steven Chu earlier said the US was keeping open the option of introducing more sanctions against Iran. The UN Security Council has already imposed three rounds of sanctions aimed at convincing Tehran to halt its uranium enrichment programme. The West believes Iran has designs on a nuclear weapons programme. Tehran insists it only plans to develop civilian nuclear energy.