This would be a second deal between Moscow and Ankara for the S-400 missile systems. Turkey has already received two batteries of the S-400s worth $2.5 billion, a deal which was inked in April 2017.

Speaking to reporters, the Russian state arms exporter Rosoboronexport chief Alexander Mikheyev said “The contract has been signed”, and stated that the parties shall now discuss the financial terms of the contract.

He further said that the timeframe of implementing the contract would depend “on our partners’ readiness to finally resolve the procedural issues with the financing of this project”.

Turkey, being the first NATO member country to have received the S-400 air defense system, has damaged its reputation among NATO members and severely strained ties with Washington.

Due to the deal, Washington kicked-out Turkey out from the F-35 Joint Strike Fighter program – which means it won’t be getting any American 5th generation fighters and could instead look at Russian Su-35 jets.Instead of trying to resolve matters with the United States, Erdogan has pushed forward for a second deal for the S-400.

Past talks between Turkey and the U.S. on the acquisition of the Patriot air defense system had fallen over a large group of issues, from the accessibility of S-400s to Ankara’s disappointment with Washington’s terms and conditions.Turkey has said it will possibly consent to an offer if it incorporates terms for indigenous production and transfer of technology.

Ankara has more than once emphasized that it was the U.S.’ refusal to sell it Patriots that drove it to search out different vendors, adding that Russia offered a superior deal, including the transfer of technology.  Turkey even proposed setting up a commission to explain any specialized issues, yet the U.S. has so far not reacted to this proposition.According to TASS, the S-400 ‘Triumf’ is the most advanced long-range air defense missile system that went into service in Russia in 2007. It is designed to destroy aircraft, cruise, and ballistic missiles, including medium-range weapons, and can also be used against ground installations. The S-400 can engage targets at a distance of 400 km and at an altitude of up to 30 km.