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.

British Prime Minister Keir Starmer said the drone threat was "a reminder of what Ukraine is facing every day."

While air raid sirens during visits by foreign leaders have sounded before, it is rare for air defenses to actually have to fight off attacking drones.