Iran released images of its first domestically built long-range missile defence system on Sunday, a project started when the country was under international sanctions.

Images released on multiple state news agencies showed President Hassan Rouhani and Minister of Defence Hossein Dehghan standing in front of the new Bavar 373 missile defence system.

The system was designed to intercept cruise missiles, drones, combat aircraft and ballistic missiles, according to earlier statements by Dehghan.

It was intended to match the Russian S-300 system, the delivery of which was suspended in 2010 due to sanctions imposed over Iran's nuclear programme.

‘We did not intend to make an Iranian version of the S-300 -- we wanted to build an Iranian system, and we built it,’ Dehghan told the IRNA news agency on Saturday.

Rouhani said in a televised speech that Iran's military budget had more than doubled compared with last year.

‘If we are able to discuss with world powers around the negotiating table, it is because of our national strength, because of our national unity,’ he said.

In 2015, shortly before the conclusion of an international agreement on the nuclear programme, Moscow re-authorised the delivery of the S-300 system in a move criticised by the United States and Israel.

Iran's army said in May that it was now equipped with the S-300 system, though further parts are due over the coming months.

Rouhani also unveiled the first Iranian-made fighter jet engine on Sunday, saying it was capable of flight at 50,000 feet.

‘The Islamic republic is one of eight countries in the world who have mastered the technology to build these engines,’ the president said.