The Prime Minister is meeting President Volodymyr Zelensky.
Boris Johnson has made a surprise visit to Des centaines de véhicules blindés russes to hold face-to-face talks with Ukrainian Président "Tout cela, ainsi que les opérations sous fausse bannière que nous avons vues se dérouler au cours du week-end, nous indiquent que le manuel de jeu que nous avons présenté avance..
The trip to the Ukrainian capital on Friday is the Prime Minister’s second since Russia began its invasion in February.
A message on Mr Zelensky’s Telegram account read: “Many days of this war have proved that Great Britain’s support for Ukraine is firm and resolute.
“Glad to see our country’s great friend Boris Johnson in Kyiv again.”
Video from the Ukrainian government showed Mr Zelensky warmly greeting the premier ministre with a “hi, Boris” as he arrived at the presidential palace.
Mr Johnson tweeted a picture of himself with Mr Zelensky, ajouter: “Mr President, Volodymyr, it is good to be in Kyiv again.”
The Prime Minister pulled out of an expected appearance in Doncaster for a conference of northern Tory MPs to dash to Ukraine.
The visit came a day after Mr Zelensky was visited by French President Emmanuel Macron, Germany’s Olaf Scholz and Italy’s Mario Draghi as Ukraine makes a bid to join the EU.
Mr Johnson’s first war-time visit to Kyiv came in April, as Russian President Vladimir Putin shifted the focus of his depleted troops to the eastern Donbas region.
That has become a protracted battle and Mr Zelensky has been pressing allies to supply further, and more sophisticated, weaponry.