Russia is likely to sign a contract for delivery of an additional batch of its S-400 missile systems to Turkey next year, the Interfax news agency cited Sergei Chemezov, head of state conglomerate Rostec, as saying on Sunday.

Turkey bought a batch of the missile systems from Russia last year, leading to its suspension by Washington from the U.S. F-35 stealth fighter jet programme. The United States has said that Turkey risks U.S. sanctions if it deploys the Russian-made S-400s.