Raytheon has received a $225m contract to provide additional Patriot missile defence capabilities for an undisclosed customer.
The customer is one of 13 nations using the Patriot integrated air and missile defence system.
Raytheon Integrated Air and Missile Defence vice-president Ralph Acaba said: "Our customer chose to continue investing in Patriot because Patriot saves lives.
"That added capability will strengthen our customer's protection against the evolving threats of tactical ballistic missiles, cruise missiles and enemy aircraft."
The long-range, high-altitude, all-weather Patriot system has been designed to counter threats from tactical ballistic missiles, cruise missiles, drones and advanced aircraft.
To date, Patriot completed more than 1,400 flight tests and 3,000 ground tests, according to Raytheon.
The latest deal follows a contract award to Raytheon from the Netherlands to begin upgrading its own Patriot systems.
Poland has also recently requested Patriot missile system from the US.
Since December 2014, the 13 Patriot partner nations have invested more than $7.2bn in the system's procurement and improvements.
The Patriot was recently upgraded with GaN-based AESA radar technology to increase its detection range and power, as well as enable 360° coverage.
The upgrades also allow the system to fire multiple missile types to destroy a range of threats.
Image: Patriot can counter threats from tactical ballistic missiles, cruise missiles, drones and advanced aircraft. Photo: courtesy of Raytheon Company.