The UK Prime Minister met European Council President Antonio Costa on the train to Kyiv on 23 August 2026, as the two leaders travelled to the city to mark Independence Day, according to a press release published on 24 August 2026 by the Prime Minister's Office, 10 Downing Street. The leaders agreed it was a vital moment to show unity and solidarity with Ukraine.

On the UK's relationship with the European Union, both underlined the importance of being ambitious to drive a step change in relations. The Prime Minister said the UK had to be bolder in getting closer to the bloc, including by building on existing close defence and security ties with European Allies to drive greater cooperation across all areas of the relationship. The leaders agreed a UK-EU summit set to be held later in the year would offer a platform to continue that work. Both said they looked forward to seeing each other at the Coalition of the Willing later that day.