Russia and Turkey are working on a contract for the delivery of a new batch of Russian S-400 missile systems.

Axar.az reports the Interfax news agency cited a senior official at a Russian military cooperation agency as saying on Friday.

Moscow hopes to seal a deal to supply Turkey with more S-400 systems in the first half of next year, the head of Russian state arms exporter Rosoboronexport said last month.

Amid already strained bilateral ties, Washington has suspended Ankara from the U.S. F-35 stealth fighter jet program, in which it was a producer and buyer, to penalize it for buying S-400 batteries this year.