DAMASCUS (AFP) - Iran said on Thursday that it hoped weekend talks aimed at defusing the long-running standoff over its nuclear drive would produce "positive developments" and voiced satisfaction at US involvement. "The presence of an American delegate in Geneva will help the United States be informed directly," Foreign Minister Manouchehr Mottaki said during a visit to Syria, Iran's closest regional ally. "We hope that the meeting in Geneva on Saturday will produce positive developments on the ground," he said at a news conference with Syrian Foreign Minister Walid Muallem. In a major policy shift by Washington, US Under-Secretary of State William Burns will attend the talks between Iranian chief nuclear negotiator Said Jalili and EU foreign policy chief Javier Solana to discuss a package of incentives offered by world powers to Tehran. Mottaki also said it was examining a reported US plan for a diplomatic presence in Tehran, which would be the first such link in nearly 30 years. "The request of the United States has been made via the media in a non-official fashion. The opening of an American interests office is the object of a study and an examination," he said. US Secretary of State Condoleezza Rice said Thursday the US is "firmly behind" diplomatic efforts to halt Iran's sensitive nuclear work but did not know if Tehran would respond positively. "The point we are making is that the United States is firmly behind this diplomacy," Rice said after deciding to send a top diplomat to Geneva talks. "Hopefully the Iranians will take that message," Rice told reporters after meeting with Alexander Stubb, Finland's foreign minister in Washington. Asked if she expected the Iranians to respond positively to a new incentives package to halt uranium enrichment work offered last month by the US and five other international partners, she replied: "I don't know." Meanwhile, US Under-Secretary of State William Burns held talks Thursday with EU foreign policy chief Javier Solana to prepare a key meeting with Iran's top nuclear negotiator this weekend. Solana's spokeswoman said that the State Department's third ranked official and the EU's top diplomat spoke in Brussels Thursday morning, ahead of Saturday's Geneva talks. It will be the first time that Washington, which broke off relations with Iran in 1980, has participated in the negotiations aimed at persuading Tehran to suspend uranium enrichment in exchange for a package of incentives. "Mr Solana told Mr Burns that his participation could only have a positive impact," said the spokeswoman, Cristina Gallach. "We hope the Iranians are going to understand the importance of this decision" to attend. Solana also spoke by telephone with representatives from the four other permanent UN Security Council members and Germany - the so-called 5+1 group - who will also take part. A senior US official said Wednesday that Burns "is there to listen, not to negotiate," but his presence at the table meets a long-standing demand from Iran to have the United States involved. The Europeans have been running these "talks about talks" since 2006, when Solana made a first offer to Tehran on behalf of the major powers of political and economic incentives in exchange for an end to enrichment. Enrichment is a process for powering a nuclear reactor, but at highly refined levels the uranium can be used to build the core of an atom bomb, which many countries fear the Islamic Republic is trying to covertly develop. Iran says its nuclear aims are only peaceful and has refused to sit down at the negotiating table if it has to suspend uranium enrichment even before the talks begin.