Russian defense leaders have formalized a new procurement pact with defense aviation firm Irkut Corporation for 30 new Su-30SM fighter jets for the country's air force.

The new multi-mission attack aircraft, dubbed the "Flanker," are expected to arrive by the end of 2018, according to the deal signed between Deputy Defense Minister Yuri Borisov and Ikrut President Oleg Demchenko. Russian defense officials released details of the buy on Monday.

Russian naval leaders already have 20 Flanker fighters on order for the nation's sea service, on top of the 30 jets under the new deal for the country's air force, according to a report in IHS Jane's Defence Weekly. The country's naval forces expect to field a total of 50 Su-30SMs as part of their fighter fleet.

Designed mainly as an air-to-air combat fighter, the Flanker was one of several fighter types deployed by Moscow to provide air support to government forces loyal to Syrian President Bashar al-Assad.

First deploying to Russia's airbase in Latakia in northwest Syria last September, the Su-30SM has conducted numerous bombing missions against anti-government rebels and Islamic State fighters near Idlib and elsewhere in the country.

The Flanker fleet reportedly played a key role in backing Assad's troops to retake the ancient city of Palmyra, which had been under IS control. Russia's air campaign in Syria has drawn rebuke from the international community, however, citing numerous cases of civilian casualties as a result of Moscow's bombs.

Russian President Vladimir Putin officially called an end to the country's air war in Syria last month. A large number of Russian military advisers and attack aircraft remain in the country, with Putin vowing Russian forces could restart aerial bombardment within hours.