Experts say this means Riyadh, traditionally a United States customer, is looking for military hardware alternatives.
U.S. North Atlantic Treaty Organisation ally Turkey also has plans to buy the S-400 system instead of the Medium Extended Air Defense System (MEADS), which is jointly built by Lockheed as well as German and Italian defense companies.
In September, Turkey finalized and made a deposit on a $2.5 billion deal for the S-400, deepening tensions between Washington and Ankara. Russian Federation might also join Saudi Arabia with additional cuts.
This sale is likely to further U.S. national security and foreign policy interests and support the long-term security of Saudi Arabia and the Gulf region.
"Even if the implementation of this agreement will be hard, it is still a sign that Saudi Arabia recognizes the need for diversification of military-technical cooperation, that the security problem of the country and neighboring countries now depends not only on the former monopolist United States but also on Russian Federation". The following month, Saudi Arabia's sovereign wealth fund committed to invest $10 billion in Russia over five years, the largest-ever foreign direct investment in the country according to the Russian Direct Investment Fund.
Saudi Arabian Military Industries (SAMI) has signed a Memorandum of Understanding (MoU) with Russia's state company Rosoboronexport for procurement of several armament systems. It is meant for destroying aircraft, cruise and ballistic missiles, including-medium range ones and can be used against ground targets.
Last week, Australia said it will outfit its new naval warships with Lockheed's Aegis air-defense system, which is also used by the US and Japan and would help the three navies coordinate on missile-defense missions.