Iran on Saturday dismissed concerns raised by five nuclear-armed states over Tehran's controversial atomic programme, saying the Islamic republic is committed to the Non-Proliferation Treaty.

"Iran is a committed member of the International Atomic Energy Agency (and) will continue its cooperation" with the UN atomic watchdog, Iran's foreign ministry spokesman Ramin Mehmanparast said in remarks reported by the ISNA news agency.

"Iran, one of the first countries to sign the NPT, adheres to its commitments to the treaty," he said, noting that Tehran's nuclear activities were monitored by the IAEA.

His comments came a day after representatives of the world's five major nuclear-armed states voiced concern over Iran and North Korea's atomic programmes at the end of their two-day preparatory meeting in Geneva ahead of the next review in 2015 of NPT.

The representatives of the United States, Russia, China, Britain and France -- the five permanent members of the United Nations Security Council and longtime nuclear-armed states -- stressed on Friday that "the fundamental importance of an effective IAEA safeguards system in preventing nuclear proliferation."

"In the context of the nuclear test conducted by (North Korea) on February 12, 2013, and the continued pursuit of certain nuclear activities by Iran ... the P5 reaffirmed their concerns about these serious challenges to the non-proliferation regime," they said in a statement.

World powers suspect Iran, which remains a signatory of the NPT, is working towards developing a nuclear weapons capacity, although Tehran insists its work is being conducted for energy and medical purposes.

Diplomatic efforts have been underway for years in which the five nuclear powers plus Germany -- known as the P5+1 -- have attempted to persuade Iran to cut back on sensitive aspects of its nuclear work.

Latest such attempts suffered a setback in Almaty on April 5-6, as the two sides appeared to be still "far apart" on key issues, according to EU's top diplomat Catherine Ashton, representing the world powers in the talks with Tehran.