US Secretary of State John Kerry is leading marathon international efforts to get Iran to agree strict limitations on its nuclear programme in exchange for ending punishing Western economic sanctions.
“I believe a good deal is at hand,” Mogherini told European lawmakers gathered in Riga where EU foreign ministers meet later Friday.
“I also believe that there is not going to be any deal if it is not going to be a good deal,” she said.
“This is something that we have to pass as a message to all our friends and partners,” she added, apparently referring to Israel which is bitterly opposed to any nuclear deal with Iran.
Mogherini said a successful outcome now depended more on political will than on technical negotiations, suggesting that some progress has been made.
Kerry held intensive talks in Switzerland earlier this week with his Iranian counterpart Mohammad Javad Zarif as the clock runs down on the end-March deadline to secure a political settlement.
A final deal is meant then to be concluded by end-June.
The so-called P5+1 group of Britain, China, France, Russia, the United States and Germany wants an accord that would prevent Tehran from developing a nuclear bomb.
In return, the West would ease damaging sanctions on Iran, which insists its nuclear programme is purely civilian.
The European Union has facilitated the talks and on Thursday hosted a technical meeting between the parties in Switzerland.
“The meetings were constructive and useful. Some progress was made and a better understanding on some of the issues emerged,” a statement issued by Mogherini’s office said.
“The (parties) will continue to work on the remaining gaps and will meet again very soon,” it added. -AFP