The European Union�s foreign policy chief said Friday he is hopeful that stalled talks with Iran over the country�s nuclear program can yield reach an agreement.

The talks between Tehran and world powers deadlocked in part over Iran�s demand for the United States to lift a terrorist designation on the country�s paramilitary Revolutionary Guard.

Speaking on the sidelines of a meeting of the Group of Seven major economies in Germany, Josep Borrell, the EU�s high representative for foreign policy, said an EU envoy visited Tehran this week for talks that had �gone better than expected.�

�The negotiations have been stalled for two months due to this disagreement about what to do with the Revolutionary Guard,� Borrell said.

�These kind of things cannot be solved overnight, but let�s say the negotiations were blocked and they have been deblocked,� he added. �Which means there is a perspective of reaching agreement.�

Iranian Foreign Minister Hossein Amir Abdollahian echoed Borrell�s assessment, saying on Twitter that the discussions between the EU envoy and Iran�s negotiator �were another opportunity to focus on initiatives to resolve the remaining issues.�

�A good and reliable outcome is within reach if US makes its decision & adheres to its commitments,� Abdollahian wrote.

Meanwhile, the EU�s envoy, Enrique Mora, said Friday that he was briefly detained with colleagues at Frankfurt Airport while transiting from Tehran to Brussels, in breach of diplomatic rules.

Mora said he had received �not a single explanation� from German authorities for why he was detained. �An EU official on an official mission holding a Spanish diplomatic passport. Took out my passport and my phones,� he wrote on Twitter.

He said the EU ambassador to the U.N. in Vienna and the head of the EU�s Iran task force were also detained.

�We were kept separated,� Mora wrote. �Refusal to give any explanation for what seems a violation of the Vienna Convention.�

Neither German police nor Germany�s Foreign Ministry responded immediately to requests for comment.

Borrell declined to speculate on the incident, saying only that �the issue is over.�

(AP)