TEHRAN: Iran will sign a contract with Russia for the purchase of Sukhoi-30 fighter jets, Iran's defence minister said Wednesday.

In comments published on the ministry of defence website, Gen. Hossein Dehghan did not specify how many fighter planes Iran will buy, or give a timeline for the signing of the deal. However, he said that under the agreement Iran would also be involved in the production of the aircraft.

Iran needs to "seriously focus on the air force and fighters," he said. "We are moving toward a contract. We told them that we need to be involved in the production (of the plane) as well."

Iran's acquisition is significant given its role as a regional power in the volatile Middle East, where it is backing opposite sides in conflicts in Yemen and Syria to its longtime rival Saudi Arabia.

The fighter jet is believed to be comparable to the American F-15E fighter bomber.

Iran's air force still heavily depends on domestically modified versions of long-outdated warplanes, including former Soviet MiGs and American F14A Tomcats from the 1970s.

Dehghan also rejected reports that Iran has negotiated the purchase of J10 fighter jets from China.

Russia has already started delivering S-300 air defence missile systems to Iran. The advanced defensive weapons system deal was frozen in 2010 due to UN sanctions.

Russian President Vladimir Putin approved delivery of the air defense missile system in April 2015, a move that will significantly bolster the Islamic Republic's military capability.

Dehghan said the first Iranian crews, who have been trained in Russia, will return home within the next two or three days and another group will be dispatched for training subsequently.

Iranian efforts to build up its air power is mostly a homegrown project, tweaking older technology or using domestic know-how to build its first generations of spy and attack drones. Iran has also made progress in developing its missile program.