Istanbul: Turkey has signed a deal with Russia to buy S-400 missile defence systems, its first major weapons purchase from Moscow, in an accord that could trouble Ankara's NATO allies.
The purchase of the surface-to-air missile defence batteries, Ankara's most significant deal with a non-NATO supplier, comes with Turkey in the throes of a crisis in relations with several Western states.
"Signatures have been made for the purchase of S-400s from Russia. A deposit has also been paid as far as I know," Turkish President Recep Tayyip Erdogan said in comments published in several newspapers on Tuesday.
"Mr Putin (President Vladimir Putin) and myself are determined on this issue," he told Turkish journalists aboard his presidential jet returning from a trip to Kazakhstan.
Moscow also confirmed the accord, with Vladimir Kozhin, Putin's adviser for military and technical cooperation, saying: "The contract has been signed and is being prepared for implementation."
The purchase of the missile systems from a non-NATO supplier is likely to raise concerns in the West over their technical compatibility with the alliance's equipment.
The Pentagon has already sounded the alarm, saying bluntly that "generally it's a good idea" for NATO allies to buy interoperable equipment.
But Erdogan said Turkey -- which has the second largest standing army in NATO after the United States -- was free to make military acquisitions based on its defence needs.
"Nobody has the right to discuss the Turkish republic's independence principles or independent decisions about its defence industry," he said.
"We make the decisions about our own independence ourselves, we are obliged to take safety and security measures in order to defend our country."
He said Moscow would extend a credit to Turkey for the purchase of the weapons.
Quoted by Russian state-owned TASS news agency, Kozhin said the deal was fully in line with Moscow's strategic interests.
"For this reason, we fully understand the reactions of several Western countries which are trying to put pressure on Turkey".
However signing the deal does not mean that delivery is imminent, with Russia facing a high demand for the S-400s from its own armed forces and key clients like China and India.
Some analysts have suggested the message sent to the West by the military cooperation between Moscow and Ankara is as important as the delivery itself.
In 2015, Turkey scrapped a $3.4 billion deal with China to build its first anti-missile system.
