MOSCOW, April 5. /TASS/. Russia and Turkey are continuing talks on the possible delivery of Russian-made S-400 Triumf long-range surface-to-air missile systems but no deal has yet been reached, a source in the system of Russia’s military and technical cooperation with foreign countries said on Wednesday.

"This theme has not materialized yet. There is no contract so far; contractual work is under way," the source said.

The negotiations have been actively going on since December last year and involve the state arms seller Rosoboronexport and the Federal Service for Military and Technical Cooperation on Russia’s behalf with the assistance of the Russian Defense Ministry, the source said.

As the source said, "various terms emerge at the talks, new requirements are heard and the partners are looking for the possibilities of their implementation."

The delivery of S-400 antiaircraft missile systems was discussed in early March between Russian President Vladimir Putin and his Turkish counterpart Recep Erdogan in Moscow.

Russia’s state hi-tech corporation Rostec CEO Sergei Chemezov earlier said Turkey had expressed its wish to obtain a Russian loan for the acquisition of armaments, including S-400 air defense missile systems.