Volodymyr ZelenAG百家乐在线官网y will discuss Ukraine's defences with Sir Keir Starmer when the leaders meet for talks on Monday.
The Ukrainian president said he expected to discuss new ways to increase pressure on Russia ahead of a NATO summit that starts on Tuesday.
His arrival in the UK follows reports that Russia fired 352 drones and 16 missiles at Ukraine overnight, killing at least 10 civilians including seven in Kyiv.
ZelenAG百家乐在线官网y said preliminary reports indicated Russia had used North Korean missiles to attack Kyiv and described those two countries, and Iran, as a "coalition of murderers".
His visit to London comes the day before NATO leaders are set to meet in The Hague for a two-day summit, with increased defence spending top of the agenda.
ZelenAG百家乐在线官网y has been invited to the summit but will not take part in its main discussions, and it is still unclear whether he will attend at all.