"Delivery of S-400 long-range air and missile defense systems resumed today," the statement said.
"The fourth Russian plane carrying S-400 parts landed at Murted Airport outside Ankara," it added.
On Friday, the ministry announced the much-awaited delivery of S-400 components had begun.
The United States has repeatedly warned it will impose economic sanctions and put aside Turkey from the F-35 stealth fighter jet program if Ankara does not drop its S-400 purchase. Turkey has refused to bow to US pressure, saying its defense purchase is a matter of national sovereignty.
The US fears that if Ankara integrates the S-400 into its defenses, data about the US-built F-35 fighter jet could leak back to the Russians, and Washington has threatened to deny Turkey access to the stealth aircraft.
Acting US Secretary of Defense Mark Esper and Turkish Defense Minister Hulusi Akar spoke by phone. While the Pentagon declined to discuss the call, the Turkish Ministry released a statement late Friday, saying Akar stressed that the purchase of S-400 defense systems "was not an option but rather a necessity" due to Turkey's security concerns.
The statement said there was no change in Turkey's "strategic orientation," adding that a deterioration in relations would not serve the interests of Turkey, the US or NATO.
The minister also emphasized Turkey's commitment to the F-35 program and repeated a proposal for a joint working group to study how the S-400 system would interact with the fighter jets.
The western defense alliance NATO, which counts Turkey as one of its members, is also "concerned about the potential consequences" of the S-400 purchase, an official said.
Members of the US Congress have repeatedly voiced opposition to the move and threatened sanctions.
Ankara rejects the US warnings, and on Friday, Foreign Minister Mevlut Cavusoglu told reporters: "We say this each time. This is a done deal. The process continues."
AFP and AP contributed to this story.