US President Barack Obama has told Iranians they "deserve better" and that a comprehensive agreement on the nuclear issue will help move Iran "along the new path that so many Iranians seek".
The US leader made the remarks on Thursday in a message marking Nowruz, the Persian new year, a day after the conclusion of the latest round of negotiations on Tehran's nuclear programme.
Iran denies seeking to to develop the capability to produce atomic weapons. The US, the European Union and the United Nations have imposed sanctions on Iran because of its refusal to suspend enrichment and other sensitive atomic activities.
In his address, Obama said: "A comprehensive agreement on the nuclear issue would help move Iran along the new path that so many Iranians seek.
"But the economic hardship that so many Iranians have endured in recent years - because of the choices of Iranian leaders - has deprived your country and the world of the extraordinary skills and contributions you have to offer. And you deserve better."
It is Obama's first Nowruz address since talks began in earnest to reach a lasting settlement about Iran's nuclear activities and the first since Hassan Rouhani was elected to the office of president.
'Substantive and useful'
On Wednesday Catherine Ashton, the European Union foreign policy chief, and Mohammad Javad Zarif, the Iranian foreign minister, told reporters in Vienna that they had held "substantive" and "useful" talks.
The P5+1, a group comprising Britain, China, France, Germany, Russia and the US, hope to honour the July deadline set in November for a long-term nuclear deal between the six powers and Iran.
That deadline was agreed as part of an interim deal, reached in November, under which Iran stopped some parts of its programme in exchange for limited sanctions relief.
Obama said: "If Iran meets its international obligations...It means more economic growth and jobs for Iranians...more opportunities for Iranian students...real diplomatic progress this year can help open up new possibilities and prosperity for the Iranian people for years to come.
"That’s the message the Iranian people sent at the ballot box last year. I hope that the entire Iranian government hears that message too."
The P5+1 and Iran are due to meet again on April 7 in Vienna.