Russian President Vladimir Putin and Turkish President Recep Tayyip Erdogan have agreed to hasten the delivery of S-400 air defense missile systems to Ankara.
"We took the decision to speed up the timetable for the delivery of these highly effective Russian systems," said Putin following talks with his Turkish counterpart in Ankara on Tuesday.
He added that the speeding up of the deal was being carried out on "request of our Turkish partners and friends."
"In the military sphere our priority is to fulfill a contract to supply Turkey with S-400 Triumph missile systems. We expect the upcoming meeting of a targeted government-level commission to thoroughly discuss future supplies of Russia's modern military production," he noted.
According to reports the deal is worth around US$2 billion, and the delivery of the S-400s was to initially begin in early 2020.
The United States has reportedly warned Turkey against the consequences of its decision to buy S-400 surface-to-air missile batteries from Russia, saying Washington could slap Ankara with sanctions over such a purchase.
The S-400, whose full name is the Triumf Mobile Multiple Anti-Aircraft Missile System (AAMS), is an advanced Russian missile system designed to detect, track, and destroy planes, drones, or missiles as far as 402 kilometers away. It has previously been sold only to China and India.
Turkey is striving to boost its air defense, particularly after Washington decided in 2015 to withdraw its Patriot surface-to-air missile system from Turkey's border with Syria, a move that weakened Turkey’s air defense.