The State Department has signed off on a request from Saudi Arabia to buy four Freedom-class littoral combat ships (LCS) from Lockheed Martin, marking a long-expected deal to strengthen the desert kingdom’s Eastern Fleet.

It would be the first export deal for the Navy’s brownwater frigate – and a significant step up in the military arms competition among Saudi Arabia and rival Iran. With the Saudis and other Gulf states uneasy over the West’s nuclear deal with Iran, U.S. officials have promised to help strengthen their forces.

The $11.25 billion deal to close late this year will include ship construction, weapons and other systems and support for four multimission surface combatant (MMSC) ships, variants of the 388’x57’x14’ Freedom-class LCS first delivered in 2008 from Marinette Marine Corp., Marinette, Wis.

One example of those LCSes is the USS Fort Worth, powered by Rolls-Royce MT30 36MW gas turbines and Fairbanks-Morse Colt-Pielstick 16PA6B STC diesels, driving four Rolls-Royce waterjets. The packaged produces a cruising speed of around 45 knots.

Saudi buyers could opt for other power. A document from the U.S. Department of Defense’s Defense Security Cooperation Agency outlines other specifics to the Saudi deal, like substituting MK-75 76mm OTO Melara gun systems in place of the BAE Systems Mk110 57mm deck gun used on earlier ships.

Other systems included in the sale will be radars, sonars, Mk-41 vertical launch systems, Harpoon, Sea Sparrow and other missiles, and Raytheon’s Mk-15 Mod 31 SeaRAM close-in missile defense system.

“The proposed sale will provide Saudi Arabia with an increased ability to meet current and future maritime threats from enemy weapon systems. The multi-mission surface combatant ships will provide protection-in-depth for critical industrial infrastructure and for the sea lines of communication,” according to the DSCA statement. “Saudi Arabia will use the enhanced capability to keep pace with the rapid advances in technology and to remain a viable U.S. coalition partner in the region.”