US Navy Opens Formal Study of Japanese, Korean and Turkish Frigates After Constellation Cancellation

The US Navy has opened a formal evaluation of three foreign frigate designs, from Japan, South Korea and Turkey, for a new class of frigates, USNI News reported on 1 September 2026. Acting Secretary of the Navy Hung Cao directed William Mahan, assistant secretary of the Navy for research, development and acquisition, to oversee a study of international combatants, as well as roll-on/roll-off and CONSOL tanker designs for Military Sealift Command. The assessment is due on 12 November 2026.

The Japanese candidate is the export version of Mitsubishi Heavy Industries' Mogami-class frigate. South Korea's entry is the Chungnam-class frigate, a six-ship program built by HD Hyundai Heavy Industries, SK Oceanplant and Hanwha Ocean. Turkey offers the Istanbul-class frigate, built by several Turkish shipyards.

The competition rests on a presidential national security memorandum of 13 August 2026, "Rebuilding the United States Navy and America's Shipbuilding Industrial Base", which sets out a "Finland Model": a foreign shipbuilder may build the first two ships of a class at its parent yard but must build "all ships after the first two such ships in United States shipyards". The supplier must also build a new US shipyard or take a majority stake in an existing one and train an American workforce, and Congress must be notified 30 days before any contract is executed.

The fiscal year 2027 budget request allocates $1.85 billion to acquire up to two foreign-built ships before construction transfers to American yards, USNI News reported on 24 April. According to The War Zone, the Senate's draft FY2027 National Defense Authorization Act would eliminate the waiver authority that allows foreign-built warships, and the House Armed Services Committee has moved to block spending on foreign-built vessels; the opposition is bipartisan and cites shipyard jobs. Navy spokesman Capt. Ron Flanders said the administration aims to "deliver ships faster while ensuring long-term investment, technology transfer, and workforce expansion within U.S. shipyards," The War Zone reported.

On 25 November 2025, then-Secretary of the Navy John Phelan announced the cancellation of the Constellation-class program. The two hulls under construction, Constellation and Congress, continue at Fincantieri Marinette Marine in Wisconsin. According to the Navy's announcement as reported by Naval News, Defense News and USNI News, the design had drifted to about 15 percent commonality with its FREMM parent instead of the planned 85 percent, adding more than $1 billion in cost and about three years of delay, with the lead ship's delivery pushed from September 2026 to late 2029.

GlobalMilitary.net data lists the Constellation class as a 7,291-ton, 151-meter frigate with 32 Mk 41 cells and service entry expected in 2029, one hull on order and one planned. The only frigate the US Navy has in commission today is the 1797 sailing frigate USS Constitution, a single active frigate against 59 for China, 18 for South Korea, 17 for Turkey and 10 for Japan in GMN's latest snapshots of the world's largest frigate fleets.

Japan's Maritime Self-Defense Force operates 10 Mogami-class frigates with 2 more fitting out, and the follow-on Upgraded Mogami, a 142-meter design with a 32-cell VLS due in service in 2028, has 5 hulls on order. South Korea operates 2 Chungnam-class frigates, in service since 2024, with 2 fitting out and 2 on order. Turkey operates 1 Istanbul-class frigate, in service since 2024, with 7 on order.

Design figures reported by The War Zone on 3 September show three ships of different size:

• Mogami: 5,500 metric tons, 436 ft, two four-round Type 17 anti-ship missile launchers, a SeaRAM close-in weapon system, a 5-inch gun and, from the seventh ship onward, a 16-cell Mk 41 vertical launch system.
• Chungnam: 4,300 tons, over 423 ft, a 16-cell K-VLS, a 5-inch gun, a CIWS and twin torpedo tubes.
• Istanbul: 3,000 tons, 371.5 ft, a 16-cell MiDLAS VLS, a 76 mm gun, a Gökdeniz CIWS and twin torpedo tubes.

GMN's Constellation vs Mogami comparison sets the two designs side by side.

Ahead of the 12 November assessment, the Senate draft's removal of the waiver authority and the House committee's spending block remain to be reconciled in the final FY2027 NDAA. No design has been selected, no contract exists and the size of the new class has not been set.