BERLIN (Reuters) - The chief of the United Nations nuclear watchdog said on Friday he hoped for an agreement with Iran on an offer to send enriched uranium abroad for further processing before the end of the year. It is a unique opportunity to move from sanctions and confrontation to the process of building...trust, Mohamed ElBaradei, director general of the International Atomic Energy Agency, told a news conference in Berlin. I believe frankly the ball is very much in the Iranian court, he added. I hope they will not miss this unique but fleeting opportunity. Iran has not yet provided a final answer to a unique international nuclear fuel offer, Mohamed ElBaradei, the outgoing head of the UN nuclear watchdog, said on Friday. I do not consider that I have received a final answer, ElBaradei said. But I also very much hope that I will get an answer pretty much soon. He added: I believe that frankly the ball is very much in the Iranian court. I hope that they will not miss this unique and fleeting opportunity ... I hope that we will get an agreement by the end of the year. ElBaradei raised doubts about the efficacy of fresh sanctions against the Islamic republic. I would hate to see that we are moving back to sanctions. Sanctions at the end of the day, in most cases, hurt the vulnerable and the innocent. It really doesnt resolve issues. It would lead to more confrontation, it would lead Iran to make possibly more provocative actions. We should do everything possible to avoid that. He said that previous sanctions, such as on Iraq before the US-led invasion in 2003, had been horrible with in the name of human rights ... an egregious violation of human rights. Mr. Saddam Hussein continued to enrich himself as a result of these sanctions. It did not hurt in any way his government, he said. If sanctions are going to be applied, we are going to need 'smart sanctions, that is targeting governments and not people, ElBaradei said. He added in a message to the Iranian leadership: You need to engage in creative diplomacy, you need to understand that this is the first time when you will have a genuine commitment by a US president to engage with you. The international community has a lot to gain by regularising relations. Iran in my view is the gate to stability to the Middle East, in Afghanistan, in Iraq, Syria, Lebanon and Palestine. Its a win-win situation.