Business Insider:
Saudi Arabia has agreed to buy the Russian S-400 air defense system, Saudi-owned al-Arabiya television reported on Thursday, on the sidelines of a visit by Saudi King Salman to Moscow.
The Dubai-based television channel also said that Saudi Arabia had signed a memorandum of understanding to help the kingdom in its efforts to develop its own military industries.
Salman arrived in Moscow on Wednesday, and it was the first time a Saudi king has ever visited Moscow.