Sir Keir Starmer will host Volodymyr Zelensky, Emmanuel Macron and Friedrich Merz in No 10 to discuss ongoing support for Ukraine.
The Ukrainian leader will visit the UK with the French President and German Chancellor on Sunday, Downing Street said.
It comes after a large-scale Ukrainian drone attack targeted St Petersburg, Russia’s second-largest city, on Saturday, underscoring Kyiv’s growing ability to hit deep inside Russia.
No casualties were immediately reported.
In Ukraine, one person was killed and three wounded overnight into Saturday in the Dnipropetrovsk region, as Russian forces struck three districts nearly 30 times with drones and artillery, regional head Oleksandr Hanzha said.
Vladimir Putin on Friday rejected a proposal by Mr Zelensky for face-to-face talks on the four-year-old war, claiming he saw “no point” in a meeting.
The so-called E3 group of nations meeting the Ukrainian leader are some of Kyiv’s staunchest allies, with the UK and France leading the “coalition of the willing” initiative to provide security guarantees for Ukraine as part of a peace process.
