NATO hopes that Turkey and the US will resolve disagreements over Ankara's intention to buy S-400 missile systems from Moscow, NATO representative told TASS.

According to him, it is up to each NATO ally to make its own decisions in regards to military procurement but it is important to use jointly the acquired technology.

The operational compatibility of armed NATO is a top priority for the alliance in carrying out operations and missions.

If Turkey buys the system, it would also be subject to sanctions under a bill President Donald Trump signed last summer, said the US Assistant Secretary of State for European and Eurasian Affairs, Wess Mitchell.

Russian President Vladimir Putin, in his turn, told reporters after talks with his Turkish counterpart Recep Tayyip Erdogan that Moscow decided to speed up the delivery of S-400 to Ankara.