The purchase of the missile systems from a non-NATO supplier is raising concerns in the West over their technical compatibility with the alliance's equipment.
Erdogan said: "The process will continue through a transfer of credit from Russian Federation to us".
Earlier on the same day, Turkish President Recep Tayyip Erdogan said that Ankara had made its first payment for the air defense systems.
France considers it inappropriate to comment on the contract between Moscow and Ankara on deliveries of Russia's S-400 air defense systems to Turkey, as it was a decision made by the country alone, French Foreign Ministry spokeswoman Agnes Romatet-Espagne said on Wednesday. "So what? Are we going to wait for you?"
The total value of the deal is believed to be around $2.5 billion.
The S-400 system boasts the ability to lock on 80 targets in a 400km radius. The Pentagon has already expressed its dissatisfaction with the arms deal. "Both Mr. [Russian President Vladimir] Putin and myself, we are determined on this issue", said Erdogan to journalists (via Hurriyet).
"No NATO ally now operates the S-400", the official noted, adding that: "NATO has not been informed about the details of any purchase".
Turkish officials have previously said that North Atlantic Treaty Organisation countries have not provided financially accessible military hardware, including an alternative to the Russian-made system.
"We have relayed our concerns to Turkish officials regarding the potential purchase of the S-400", Pentagon spokesman Johnny Michael told CNBC in a written statement on September 12.
The S-400 is Russia's most advanced long-range anti-aircraft missile system and can carry three types of missiles capable of destroying targets including ballistic and cruise missiles. As the dispute unfolded, the U.S. in 2015 withdrew its Patriot missiles from Turkey's border with Syria after a two-year deployment.