WASHINGTON

The US State Department approved the possible sale of the Naval Strike Missile Coastal Defense System and related equipment to Bulgaria, the Pentagon said Monday.

The estimated cost is $620 million, the Defense Security Cooperation Agency said in a statement.

"The proposed sale will enhance Bulgaria’s capability to meet current and future threats by providing a credible force that is capable of deterring adversaries and participating in NATO operations," it added.

The principal contractor will be Kongsberg Defence and Aerospace AS, located in Kongsberg, Norway.

The Defense Security Cooperation Agency delivered the required certification notifying Congress of this possible sale on Monday.