Tokyo and London leaders deepen ties on AI, climate and finance

Tokyo Gov. Koike Yuriko met London Mayor Sadiq Khan and City of London Lady Mayor Susan Langley in Tokyo on June 18 to expand cooperation on climate action, artificial intelligence and financial services. The talks and a follow-on finance seminar underscored both cities’ effort to turn a 2017 memorandum into more concrete investment, innovation and policy links.

Why it matters: - Tokyo and London are aligning two of the world’s biggest city economies on issues that are reshaping growth: AI, climate action and financial services. - The talks point to possible cross-border cooperation on AI governance, transition finance and investment flows between Japan and the UK. - The meetings also signal that city leaders want to use their global reach to influence how emerging technologies and capital markets develop.

What happened: - Tokyo Gov. Koike Yuriko separately hosted London Mayor Sadiq Khan and City of London Lady Mayor Susan Langley at the Tokyo Metropolitan Government building on June 18. - Only the start of each meeting was open to the media. - Koike and Khan discussed AI, climate change, air quality, culture, fashion and tech. - Koike and Langley later held a joint news conference and said Tokyo and London will keep strengthening financial ties. - A financial seminar, the Tokyo-London Financial Innovation Seminar 2026, followed the meeting and was co-hosted by the Tokyo Metropolitan Government and the City of London Corporation.

The details: - Tokyo and the City of London base their financial cooperation on a memorandum of understanding signed in 2017. - The MOU was updated last September to support financial innovation and boost investment between Japan and the UK. - Koike said Tokyo’s exchanges with London in the financial sector are very strong and said the revised MOU would further strengthen cooperation. - Langley said the two sides discussed mobilizing finance for the global energy transition. - Langley said she expects “tangible outcomes” from the MOU. - Mayor Khan said he wanted close cooperation on AI and on climate change and air quality. - Koike said she hoped the two cities could cooperate more on climate change after London’s planned climate action awareness event the following week. - Khan later wrote on social media that the two cities discussed strengthening ties, tackling the climate emergency and leading the AI revolution. - Khan’s press office said the leaders discussed the shared challenges posed by AI and how new technologies should benefit people in both cities. - Koike said at a later news conference that AI is advancing rapidly and is already transforming society. - Koike said AI could help guide education, inform citizens about careful use of AI and streamline metropolitan administration. - The Tokyo Metropolitan Government has been working under its 2025 AI Strategy to improve administrative operations and resident services. - Khan announced London’s new AI and Jobs Taskforce in April to review AI’s impact on jobs in the UK capital. - Khan visited Tokyo after Singapore as part of a two-city Asian trade mission. - He attended the World Cities Summit in Singapore before traveling to Japan. - His Tokyo trip coincided with the Group of Seven summit in the French city of Evian, where leaders and tech executives discussed controls on powerful AI systems. - Koike and Khan are founding members of the Mayors AI Forum, launched in April by Bloomberg Philanthropies and Johns Hopkins University. - Other founding members include the mayors of Bogota, Boston, Buenos Aires, Kyiv, Madrid, Nairobi, San Antonio and San Francisco. - Koike said cities should share what they learn about both the benefits and risks of AI. - Koike and Langley also discussed women’s empowerment. - Langley said she was proud that Tokyo and London, two leading financial centers, are both led by female leaders. - Koike and Khan were first elected to their current posts in 2016 and are serving their third four-year terms. - Koike and Khan previously met in London in 2018 and 2023. - In 2023, they discussed energy, climate action and educational exchanges and agreed to promote Tokyo-London ties as friendship cities. - Langley began a one-year tenure as Lady Mayor last November. - She visited Tokyo in mid-2024 as Sheriff alongside then-Lord Mayor Michael Mainelli and met Koike then as well. - Langley said exchanges such as the seminar and secondments of Tokyo Metropolitan Government staff to the City Corporation have strengthened the relationship. - The 2026 seminar featured Koike, Langley and about a dozen other international speakers, including Greg Gardner of the British Embassy in Tokyo, Masao Shimazaki of Japan’s Financial Services Agency and representatives of fintech companies. - The seminar also included one-on-one business meetings, fintech pitches and a networking session at Tokyo Innovation Base, a TMG hub for startups, investors and local governments. - Langley wrote on social media that the UK and Japan have clear opportunities to deepen collaboration, especially in capital markets and transition finance. - Langley said diversity is key to long-term competitiveness and that she wants to keep strengthening ties between Japanese companies investing in the UK and UK businesses operating in Japan.

Between the lines: - The repeated emphasis on AI and finance suggests Tokyo and London see city-to-city diplomacy as a practical way to shape regulation, investment and talent flows before national policy fully catches up. - The focus on transition finance and energy transition shows both sides are trying to connect climate policy with capital market opportunities. - The female leadership angle adds symbolism, but the more concrete signal is the effort to convert an existing MOU into measurable business and policy outcomes.

What's next: - Tokyo and London are expected to keep building on the 2017 MOU and its 2025 update. - The two cities will likely continue sharing AI policy ideas through the Mayors AI Forum and related administrative work. - Further seminars, staff exchanges and business matching events appear likely as both sides look for follow-through on investment and innovation. - London’s climate and AI initiatives, along with Tokyo’s own AI strategy, will provide the next test of whether the partnership produces practical results.

The bottom line: - Tokyo and London are moving beyond symbolic friendship toward a working partnership on AI, climate and finance, with both city halls looking for concrete outcomes.