As the UK–Japan relationship enters a new chapter under Prime Minister Takaichi and Prime Minister Sir Keir Starmer, we are pleased to share a curated summary of the key announcements and strategic outcomes from their bilateral meeting at Downing Street, London on 14 June 2026.

Key Developments

• UK Prime Minister Sir Keir Starmer hosted Japanese Prime Minister Sanae Takaichi at Downing Street, where the leaders marked an upgrade in the UK-Japan strategic partnership and reaffirmed closer cooperation on shared global priorities, including defence, supply chain resilience, free trade and regional stability.

   

• The UK and Japan announced a major investment package worth more than £18bn in expected economic gains, including over £9bn in Japanese investment across UK infrastructure, real estate and financial services, and up to £9bn to support offshore wind development.

   

• The UK-Japan Frontier Technology Partnership will strengthen cooperation between British research and software expertise and Japanese manufacturing capability, with a focus on artificial intelligence, semiconductors, quantum computing, cybersecurity, space, advanced connectivity, nuclear technologies and healthcare innovation.

   

• The UK and Japan issued a Joint Declaration on Economic Security Cooperation, setting out closer alignment on trade and investment security, resilient supply chains, energy security, critical minerals, public-private collaboration and the rules-based international trading system.

   

UK-Japan Deal to Boost Jobs and Growth

The investment announcement centres on more than £18bn in expected economic gains for the UK, including over £9bn in Japanese investment across infrastructure, real estate and financial services, and up to £9bn for offshore wind. The package is expected to support tens of thousands of jobs and strengthen key British industries, including clean energy, infrastructure development, life sciences and financial services.

Major Japanese investors named in the announcement include Mitsubishi Estate, Mitsui Fudosan, Nomura Real Estate, Mizuho Financial Group, Hitachi and Eisai. Planned projects include new real estate developments, high-quality office space, innovation hubs, investment in housing, expanded financial services activity, and new life sciences manufacturing capacity in Hatfield.

A central element of the package is the UK-Japan Offshore Wind Compact, designed to support Japanese investment in 5.9 gigawatts of floating offshore wind projects, including developments in Scotland and the Celtic Sea. Once built, these projects are expected to generate enough clean electricity to power 8 million homes, while supporting the UK’s wider clean energy and energy security ambitions.

Associated commercial agreements include cooperation in grid infrastructure, nuclear technology and fusion energy, including new investment from Hitachi and deeper collaboration involving Rolls-Royce, the Japan Atomic Energy Agency, the United Kingdom National Nuclear Laboratory and national fusion research bodies.

UK-Japan Frontier Technology Partnership

The UK-Japan Frontier Technology Partnership marks a significant step in deepening bilateral cooperation on science, technology and innovation. Building on existing partnerships in cyber, semiconductors, digital technology, economic security and industrial strategy, the agreement brings together the UK’s strengths in research, software and innovation with Japan’s advanced manufacturing and hardware capabilities.

The partnership focuses on critical and emerging technologies that are increasingly central to economic growth, national security and global competitiveness. Key areas of cooperation include AI, quantum technologies, cyber security, space, advanced connectivity, defence and dual-use technologies, civil nuclear, fusion energy, biological security and healthcare research.

A central aim of the partnership is to support secure, trusted and commercially scalable innovation. This includes coordinated R&D support, closer links between industry and government, mobilisation of private capital, and cooperation on international standards and regulation. The agreement also highlights the importance of protecting critical technologies while maintaining open and trusted international research collaboration.

UK-Japan Joint Declaration on Economic Security Cooperation

The UK-Japan Joint Declaration on Economic Security Cooperation sets out a coordinated approach to strengthening economic resilience, trade and investment, supply chain security and critical technologies. Building on the Hiroshima Accord and the wider UK-Japan strategic partnership, the declaration reflects both countries’ shared focus on protecting economic stability in a more complex global environment.

Key areas of cooperation include investment security, public-private dialogue, resilient energy and critical mineral supply chains, and closer coordination between government, industry and financial institutions. The declaration also highlights the importance of secure and transparent supply chains, particularly in sectors such as offshore wind, battery materials, recycling and other strategically important industries.

The UK and Japan also committed to deepening cooperation on innovation, venture capital, start-ups, research security and the protection of critical technologies. Defence industry collaboration is included as part of this wider economic security agenda, with the Global Combat Air Programme recognised as an important driver of industrial and technological cooperation.

The declaration further reaffirms both countries’ support for a rules-based international trading system, including the World Trade Organisation, the Comprehensive and Progressive Agreement for Trans-Pacific Partnership, and the Japan-UK Comprehensive Economic Partnership Agreement.

Q&A

What was announced by the UK and Japan?
The UK and Japan announced a broad deepening of their bilateral partnership, covering investment, technology, defence, economic security, supply chain resilience and trade. The announcements followed a meeting between UK Prime Minister Sir Keir Starmer and Japanese Prime Minister Sanae Takaichi.

Which sectors are most directly covered?
The announcements span several strategically important sectors, including clean energy, infrastructure, real estate, financial services, life sciences, advanced manufacturing, artificial intelligence, semiconductors, quantum computing, cyber security, nuclear technology and defence.

What is the UK-Japan Frontier Technology Partnership?
The UK-Japan Frontier Technology Partnership is a framework for closer cooperation on critical and emerging technologies. It brings together the UK’s strengths in research, software and innovation with Japan’s advanced manufacturing and hardware capabilities.

What is the Joint Declaration on Economic Security Cooperation?
The Joint Declaration sets out a coordinated approach to economic security between the UK and Japan. It focuses on areas such as investment security, resilient supply chains, energy security, critical minerals, public-private cooperation and the rules-based international trading system.

Sources

• GOV UK: PM meeting with Prime Minister Takaichi of Japan: 14 June 2026 (14 June 2026)

• GOV UK: Tens of thousands of new jobs and more than £18 billion boost to British economy as Prime Minister meets Japanese leader (14 June 2026)

• GOV UK: UK-Japan Frontier Technology Partnership (14 June 2026)

• GOV UK: UK-Japan Joint Declaration on Economic Security Cooperation (14 June 2026)