Saudi Arabia is modernizing its eastern fleet to counter Iranian forces marshalled across the oil-rich Gulf.
The four ships to be delivered are based on the US Navy's littoral combat ship. While relatively small, the warships are designed as fast and maneuverable in shallow waters and pack a lethal array of weaponry for their size.
The Defense Security Cooperation Agency released the advisory saying had just notified the US Congress of the State Department's decision and was awaiting final approval.
In a statement, the agency said the sale would "improve the security of a strategic regional partner, which has been and continues to be an important force for political stability and economic progress in the Middle East."
Described as a "multi-mission surface combatant ship" in its export version, the ships carry dozens of Sea Sparrow anti-aircraft missiles and Harpoon anti-ship missiles.
Its main gun is Italian built 76mm OTO Melara, but the main contractor for the vessels will be the US arms giant, Lockheed Martin.
If approved as is expected, the sale underscores a renewed arms race in the Middle East.
Russia has recently stepped up military support for Syria, a bitter foe of Saudi Arabia, and Egypt, an ally of Saudi Arabia just agreed to buy two helicopter carriers from France.
Saudi Arabia has also been under pressure from the Islamic State, or ISIS, for bowing to Western pressure and facilitating a strong U.S. presence in the Middle East.