British Prime Minister Keir Starmer concluded a "landmark 100-year" security and economic partnership with Ukrainian President Volodymyr Zelensky on his first visit to the country since becoming U.K.

Britain has been at the forefront of western countries offering military support for Ukraine since Russia’s full-scale invasion began in February 2022, but the question of whether the UK would put troops on the ground to help guarantee any peace deal will be a big test for Starmer.