![Biggest arms seller countries](http://www.aljazeera.com/mritems/imagecache/mbdxxlarge/mritems/Images/2017/10/7/737616b982a54e1ea1f3eb20cd761737_18.jpg)
The United States has approved a $15bn deal to supply Saudi Arabia with the THAAD missile defence system, one of the most capable systems of its kind in the world.
If Congress does not raise an objection within 30 days, the deal will result in a massive windfall for Lockheed Martin, the world's biggest arms producer.