Iran plans to boost its ballistic and cruise missile capacity, as well as acquire new generation fighter planes and submarines, the Iranian state news agency IRNA quoted a senior Defence Ministry official as saying on Saturday.

Iran says its missile programme is solely defensive in nature and is not negotiable as demanded by the United States and European countries. Tehran says its plans to develop missiles are not linked to its 2015 nuclear accord with world powers.

"Increasing ballistic and cruise missile capacity ... and the acquisition of new generation fighters and heavy and long-range vessels and submarines with various weapons capabilities are among the new plans of this ministry," said Mohammad Ahadi, deputy defence minister for international affairs, IRNA said.

Speaking to Tehran-based foreign military attaches, Ahadi said international sanctions had failed to hamper the development of Iran's arms industry.

"We have the necessary infrastructure and what we need to do is research and development, and at the same time upgrade and update the defence industry while relying on the country's very high scientific capacities and tens of thousands of graduates in technical fields and engineering," Ahadi was quoted as saying.