Saudi Arabia “betrays” US, here's the deal he did with Russia.

The historic visit of Saudi Arabia's King Salman bin Abdulaziz Al Saud to Moscow has been accompanied by an agreement between the two countries. Riyadh has agreed to buy the S-400 air defence system from Russia, according to Saudi al-Arabiya television station.

A memorandum of understanding has reportedly been signed to help the kingdom develop its defence industries.

Russian Deputy Prime Minister Dmitry Rogozin has stated that Riyadh is showing interest in buying Russian missile systems.

Of course, there is some interest. The S-400 talks are under way, but there are still no final decisions”, he said today, adding that confidential negotiations on military-technical co-operation were under way.

S-400 is Russia's most advanced anti-aircraft missile system and has three kinds of skills to destroy targets, including ballistics and floating missiles.

The system is able to track and engage up to 300 targets at a height of 27km at the same time.

Saudi Arabia has traditionally acquired protective equipment from the United States.

In June, the kingdom signed its largest defence contract to buy American High Protection System (THAAD), aircraft soldiers, etc.

Earlier this year, Turkey signed an agreement to buy the S-400 missile system from Russia with shipments reportedly beginning within two years.