President Recep Tayyip Erdogan says Turkey continues to make payments under a deal with Russia to purchase advanced S-400 air defense missile systems, which Washington has warned could put Ankara at risk of US sanctions.

“The S-400 holds an important place in our talks. The United States� arguments are very wrong. We finished the S-400 process and our payments continue,” Erdogan told reporters in Istanbul on Friday.

He emphasized that the United States had not presented the same terms when it offered to sell Patriot missiles.

Turkey ignores US threats over Russian S-400

Turkey is ignoring threats by top US officials to buy Russia’s S-400 missile system.

Russian presidential aide Yury Ushakov told reporters in Moscow on Friday that the delivery of S-400 systems from Russia to Turkey may be on the agenda in a meeting between Russian President Vladimir Putin and his Turkish counterpart next week.

Turkish Foreign Minister Mevlut Cavusoglu said on Thursday that the purchase is a “done deal” and cannot be cancelled.

Turkey rejects stepping back from Russia arms deal

"The S-400 deal is a done deal and we will not step back from this," the Turkish foreign minister says.

“We have told them (Americans) I don�t know how many months ago or years ago that it�s a done deal, so we cannot cancel it,” Cavusoglu said at a news conference on the sidelines of a visit to the United States.

He said Turkey would like to purchase the Patriot systems, but it would not back out of its deal with Russia.

Cavusoglu further highlighted that the United States could not guarantee it would be able to sell the Patriot systems to Ankara due to an impasse in US Congress.

Turkey to honor Russia deal as US vows to ban F-35 jets

Turkey says it will honor the deal to purchase S-400 defense systems from Russia after despite US threats to ban the transfer of F-35 fighter jets to Ankara. 

“The real problem is this: even today, the United States cannot give guarantees about selling the Patriots to Turkey. Can they give them tomorrow? They can’t guarantee it. Then who will meet my needs?” he said.

The US announced on Monday that it would be suspending all “deliveries and activities” related to Turkey�s procurement of F-35 stealth fighter jets over Ankara�s plans to purchase the S-400.

US presses Turkey not to buy Russian missiles

The United States warns Turkey not to purchase Russian-made S-400 missile defense, saying the system posed a threat to NATO member states.

Moscow and Ankara finalized an agreement on the delivery of the S-400 in December 2017.

Back in April 2018, Erdogan and Putin said in Ankara that they had agreed to expedite the delivery of the S-400. At the time, it was said that the delivery could be made between late 2019 and early 2020.

A number of NATO member states have criticized Turkey for its planned purchase of the S-400, arguing the missile batteries are not compatible with those of the military alliance.

They also argue that the purchase could jeopardize Ankara�s acquisition of F-35 fighter jets and possibly result in US sanctions.

US warns Turkey of �grave consequences� over S-400 deal

The Pentagon threatens Turkey with "grave consequences" if Ankara does not drop its plan over the deployment of Russian-made S-400 missile system.

The S-400 is an advanced Russian missile system designed to detect, track, and destroy planes, drones, or missiles as far as 402 kilometers away. It has previously been sold only to China and India.

Ankara is striving to boost its air defense, particularly after Washington decided in 2015 to withdraw its Patriot surface-to-air missile system from Turkish border with Syria, a move that weakened Turkey’s air defense.

Before gravitating towards Russia, the Turkish military reportedly walked out of a $3.4-billion contract for a similar Chinese system. The withdrawal took place under purported pressure from Washington.

�Turkey to start Russian S-400 deployment in October�

Hulusi Akar said Turkey’s purchase of the S-400 is “not a choice but a necessity.”

Ankara’s ties with its Western allies in NATO have been strained over a range of issues.

Erdogan has been critical of Washington for supporting Kurdish groups in Syria that he says are responsible for terror attacks inside Turkey, among other issues.

The Turkish leader has also slammed US officials for rejecting his requests to hand over Fethullah Gulen, a powerful opposition figure living in the United States, whom Ankara accuses of having masterminded a coup attempt in July 2016.