TEHRAN - Deputy Commander of Iran's Air Force Azizollah Nasirzadeh said Iran's Defense Ministry is conducting studies to build vertical take-off and landing (VTOL) fighters, the semi-official ISNA news agency reported on Wednesday.

Referring to the country's currently-used fighter jets, Nasirzadeh said "our fighters are one of the most updated fighters, " said the report.

Iran's air force and armed forces can give tough response to any threat, he was quoted as saying.

In June 2011, Nasirzadeh said the F-14 fighter jets of Iran's Air Force continue to operate despite Washington's sanctions and restrictions.

"Although there exist restrictions and sanctions on Iran regarding the procurement of equipment in all sectors, these sanctions are double as severe when it comes to F-14 fighter jets because the aircraft was only used in the U.S. and Iran," said Nasirzadeh.

"Today, technicians of Iran's Air Force do reverse engineering, and all parts required by this kind of fighter jets are made or upgraded inside the country and installed on the aircraft," he said.

Upgraded and improved, F-14 fighter jets in Iran are used for training and conduct tactical drills on a regular basis, said the commander.

Nasirzadeh said that local experts and technicians are capable of maintaining F-14 fighters as well as other aircraft of the Iranian Air Force.

In March 2011, another commander of Iran's Air Force Mohammad Alavi said that Iran's Air Force had launched a squadron of domestically-built Saeqheh (Thunderbolt) fighter jets.

The experts have managed to mass-produce the fighter jets which were outfitted with revamped equipment and well prepared to defend the skies of the country, Alavi said.