The Russian president made the remarks at a press conference on Tuesday with his Turkish counterpart, Recep Tayyip Erdogan, in the Turkish capital, Ankara.
“We took the decision to speed up the timetable for the delivery of these highly effective Russian systems,” Putin said after talks with Erdogan.
He said that acceleration of production of the weapons was being done at the “request of our Turkish partners and friends”.
The deal has been valued at about $2bn, according to reports.
Such a major purchase of weaponry from Russia by a key NATO member had raised concerns both over Turkey’s strategic orientation and the compatibility of the systems within the alliance.
But Erdogan indicated that Turkey was in no mood to listen to criticism from the West over the purchase.
“This is a decision of Turkey. We made an agreement about the S-400s [with Russia] and this issue is now closed,” he said.
Turkish-Russian relations have been growing increasingly warm.
The sides finalised the deal for Turkey to purchase S-400 missiles, despite NATO’s concerns in December 2017, and Russia has been building Turkey’s first nuclear power plant.
Yuri Ushakov, Russia’s presidential aide, said on Monday that Moscow will exert every effort for completing the delivery of air defence systems S-400 to Turkey by 2020.
Meanwhile, the power plant’s first reactor is expected to begin working in 2023, according to Russian media.
In the press conference, Putin also expressed hope that a meeting of the world’s chemical weapons watchdog would put a “full stop” to the issue of an ex-spy whose poisoning in Britain has been blamed on Moscow.
“We hope that during those discussions a full stop will be placed on [the issue of] what happened” to former spy Sergei Skripal, Putin said before the meeting on Wednesday of the Organisation for the Prohibition of Chemical Weapons.