The U.S. Navy is adding the GPS guidance to the SM-6 Block IA so that it has the capability to strike surface targets if needed, but given its higher cost than other land attack weapons like the Tomahawk cruise missile it would not likely be used as a primary option.[18][19] In February 2016, Secretary of Defense Ashton Carter confirmed that the SM-6 would be modified to act as an anti-ship weapon.[20]