The Turkish military is checking the S-400 air defence systems and preparing them for deployment, Defence Minister Hulusi Akar stated on Saturday.
He stressed, however, that "the purchase and planned check-ups of the air defence systems do not mean that the country is alienating itself from NATO".
The Defence Ministry stressed that the purchase does not violate Turkey's obligations as a member of the alliance and asked NATO to point out an alternative to the air defence system, instead of criticising the deal.
Earlier this week, Akar confirmed that Turkey had conducted tests of the air defence systems in Sinop, noting that the drills were scheduled in accordance with the contract.
Moscow and Ankara signed a loan agreement for the delivery of the S-400 systems in December 2017, and last year several batteries worth $2.5 billion were sent to Turkey.
The deal prompted a major backlash from Washington, with the US claiming that the S-400 is incompatible with NATO security standards and could compromise the F-35 programme.
The US even suspended Ankara from the project, warning its NATO ally that it may be completely excluded from it, but Turkey has refused to break its deal with Moscow and has reportedly vowed to activate the missile systems despite American sanctions.