Javier Solana, the EU foreign policy chief, will meet Iran's chief nuclear negotiator, Ali Larijani, next week to try to clear up ambiguities in Tehran's 21-page reply to a major power offer of co-operation if it stops work that could lead to building a bomb.
Dimitrij Rupel, the Slovenian foreign minister, said after the 25 ministers discussed the issue at a meeting in Finland: "We give Solana two weeks for his clarification talks."
Iran did not adhere to an August 31 deadline set by the United Nations security council for it to halt uranium enrichment and has given no sign it is prepared to meet the conditions set for opening negotiations on economic, technological and political co-operation.
Mahmoud Ahmadinejad, the Iranian president, was quoted on Saturday by the Iranian Student's News Agency as saying: "Our nation is a supporter of peace, but it will not retreat an iota from its right to nuclear technology."
EU ministers declined to talk publicly of sanctions if Tehran did not comply and stressed their preference for dialogue.
Frank-Walter Steinmeier, the German foreign minister, said: "Despite our intensive efforts of the last six months, there has up to today unfortunately been no signal of reciprocity from Iran,"
But he added: "We in the EU and Germany have no interest in an escalation in the coming days and weeks due to deliberations in the security council.
"That's why we and the EU foreign policy chief will neglect no opportunity to keep trying to find out through talks whether there is a possibility to return to the negotiating table."