$1 billion boost for AUKUS: US expands submarine support to UK

March 23, 2026, by Fatima Bahtić

The US has approved a potential $1 billion foreign military sales package to the UK, expanding technical and engineering support for next-generation nuclear-powered submarines developed under the AUKUS partnership.

The US State Department has formally notified Congress of a major expansion in submarine cooperation with the United Kingdom, approving a potential $1 billion package of technical support, systems integration, and personnel exchanges tied to the AUKUS submarine program.

The notification covers a wide array of advanced submarine warfare capabilities. These include technical assistance for the design and development of AUKUS-specific vertical deployment tubes, common weapon launchers, and key components of a federated submarine combat system architecture. The package also includes simulation equipment, testing and installation tools, software and source code, and extensive engineering and logistics support.

A notable element of the deal is the inclusion of embedded US and UK personnel, who will be stationed across facilities in both countries to directly support submarine design and integration efforts. The arrangement underscores the level of industrial and operational integration envisioned under AUKUS, which also includes Australia.

The newly notified package represents a significant expansion of an existing FMS case previously valued at $50 million, which covered early-stage engineering, combat system integration, and support services. With the revised ceiling now reaching $1 billion, the program is entering a more advanced and resource-intensive phase.

According to the US government, the proposed sale is intended to strengthen a NATO ally and enhance maritime security in northwestern Europe. The support will enable the UK to develop and field an ‘effective’ undersea deterrent capable of addressing evolving threats while protecting critical maritime infrastructure.

The industrial component of the program brings together major US defense contractors, including Huntington Ingalls Industries, General Dynamics Electric Boat, General Dynamics Mission Systems, Lockheed Martin, Progeny Systems, and Systems Planning and Analysis.