MOSCOW—Azerbaijan can buy 100 more Russian battle tanks after receiving $1 billion worth of this and other military hardware, Russia’s main government agency overseeing arms deals with foreign states said on Friday.

 

Konstantin Biryulin, the deputy head of the Federal Service for Military-Technical Cooperation, told the Itar-Tass news agency that Russian defense companies have all but completed the delivery of those offensive weapons, including around 100 T-90 tanks, which began last year.

“We finished the shipment of the entire batch — 100 tanks — about a month ago,” Biryulin said, citing Russian-Azerbaijani defense contracts signed in 2011.

The Russian official went on to reveal that the contracts give Azerbaijan an option to purchase another 100 T-90s. “But the second part has not been contracted yet,” he added.

The Russian arms deliveries to Azerbaijan caused a stir in Armenia after being disclosed by a Moscow newspaper a year ago. The outcry intensified after Azerbaijani President Ilham Aliyev said in August that the total volume of defense contracts with the Russians is “measured at $4 billion.”

Armenian politicians, most of them in opposition to President Serzh Sargsyan, and pundits accused Moscow of acting against the spirit of the Russian-Armenian military alliance. Russian security officials dismissed the criticism.

The Armenian government refrained from publicly adding its voice to that criticism. Some of its top representatives implied that the arms sales to Armenia’s arch-foe will be offset by more Russian military assistance to Yerevan.

Armenia’s Defense Ministry on Friday refused to comment on Moscow’s apparent readiness to sell more tanks to Baku. Biryulin’s revelation is certain to spark fresh anti-Russian statements by Armenian opposition groups and the media.

That Russia is ready to sell additional weapons to Azerbaijan was indicated by General Valery Gerasimov, the chief of the Russian army’s General Staff, during a visit to Baku last month. Later in April, an aide to the Azerbaijani minister of defense industry expressed hope that Moscow will solidify its status as Azerbaijan’s number one supplier of military equipment.

The Azerbaijani military has received Russian tanks, armored vehicles, artillery systems, attack helicopters and other offensive weapons as part of a massive build-up which Baku hopes will help it regain control over Nagorno-Karabakh and Armenian-controlled districts surrounding it.

Armenia relies heavily on Russia in the intensifying arms race with its oil-rich enemy. A military alliance with Moscow has enabled it to get large quantities of Russian weaponry at knockdown prices or even free of charge.

The closely integrated armed forces of Armenia and Nagorno-Karabakh are not known to have T-90 tanks in their arsenal. The vast majority of several hundred tanks possessed by them are less advanced T-72 models.

A Moscow-based defense think-tank reported last November the Defense Ministry in Yerevan contracted a Polish company in 2012 to modernize 84 Armenian tanks by the end of 2015. Those T-72s are supposed to have stronger dynamic armor, more powerful engines, new machine guns, surveillance cameras and state-of-the-art communication systems. Some defense experts believe that these upgrades will make them analogous to T-90s.