Turkey has begun work on its first long-range regional air and missile defence system, named Siper (bulwark or shield), Turkish President Recep Tayyip Erdogan announced on 31 October.
The project involves the state-owned Turkish Scientific and Technical Research Board (Tübitak) Defence Industry Research and Development Institute (SAGE), Aselsan, and Roketsan.
"The first delivery is expected at the end of 2021," Erdongan said.
It is unclear whether the Siper project is the new name of the Hisar-U national long-range SAM system Turkey plans to develop, as several Turkish defence experts have tweeted.
İsmail Demir, President of the Turkish Defence Industries Undersecretariat (SSB), told the state-run Anatolia news agency on 19 October that development of the Hisar-U would draw on co-operation with Eurosam and on the S-400 surface-to-air missile system Turkey hopes Russia will deliver in July 2019.