Turkey's Erdogan says Russian S-400s will be fully deployed by April 2020

Turkish President Tayyip Erdogan said on Monday that the Russian S-400 missile defence system, parts of which have been delivered to Turkey over the past four days, is expected to be fully deployed in April 2020.

Turkey's purchase of the Russian system has raised tensions with the country's NATO allies, particularly the United States, which has warned Turkey the move would trigger U.S. sanctions.