国际英语新闻：U.S. hopes for high-level meeting with Iran, world powers in weeks

According to the proposal, the enriched uranium with higher purity would be then transported back to Iran, used as nuclear fuel in research nuclear reactor for the manufacture of medical radioisotopes. But Iran has not implemented the proposal.

Turkey, Iran and Brazil signed an agreement on May 17, dubbed Tehran declaration, in which Iran committed itself to giving 1,200 kg of its 3.5 percent enriched uranium to Turkey in exchange for 20 percent enriched uranium it will receive from Western countries to be used as fuel in the nuclear research reactor in Tehran.

Despite the deal, the UN Security Council still adopted Resolution 1929 in June to impose the fourth round of sanctions on Iran since 2006.

Since then, the U.S., EU and Canada have announced that they will impose more sanctions on Iran that go beyond UN resolution.

Iran's representative to IAEA said on Monday that Iran is ready to resume talks over its nuclear fuel swap without conditions.