President Hassan Rouhani has said Iran would never build nuclear weapons.
Rouhani also said he had full authority to negotiate over Tehran's controversial uranium enrichment programme with the West.
Iran is under UN and Western sanctions over its controversial nuclear programme.
According to the BBC, the country has said it is enriching uranium for peaceful purposes, but the United States and its allies suspect Iran's leaders of trying to build a nuclear weapon.
The head of Iran's nuclear agency said that he expected a breakthrough this year in settling the nuclear issue with the West, the report said.
Ali Akbar Salehi said that they were very optimistic about the process that has started to resolve the nuclear issue.
Rouhani is due to visit New York next week for a meeting of the UN General Assembly.
