The King has met Ukrainian President Volodymyr Zelensky at Windsor Castle.
Charles welcomed the leader to an audience, followed by lunch, at the Berkshire royal residence on Monday.
Mr Zelensky has travelled to the UK to meet Prime Minister Sir Keir Starmer and discuss his country’s defences and new ways to increase pressure on Russia ahead of a Nato summit that starts on Tuesday.
The Ukrainian president was dressed in a black blazer and black trousers, rather than his usual combat fatigues, for his trip to the castle.
Charles and Mr Zelensky were pictured chatting as they made their way through the historic residence, and smiling as they shook hands in the Grand Corridor.
The King and the Ukrainian leader have met numerous times before including in March when Charles invited him an audience at Sandringham in Norfolk, and last July at the European Political Community summit at Blenheim Palace in Oxfordshire.
Mr Zelensky’s 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.
Mr Zelensky 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.
Mr Zelensky 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.
