President Zelensky described it as an “excellent” conversation in which the leaders agreed to “write a new story” in Ukraine-UK relations, while maintaining “ full support in the face of Russian aggression”.
Mr Zelensky held a close relationship with former Prime Minister Boris Johnson, who was in office when Russia invaded Ukraine in February, and whom he previously described as a “true friend”.
During the recent Tory leadership contest, the Ukrainian government appeared to express a desire to see Mr Johnson return to power when it posted a now-deleted tweet saying “better call Boris”.
Of Mr Sunak’s call with Mr Zelensky on Tuesday night, a Downing Street spokesperson said: “The Prime Minister said the United Kingdom’s support for Ukraine would be as strong as ever under his premiership, and President Zelensky could count on his Government to stand in continued solidarity.
“The Prime Minister also noted the importance of the International Atomic Energy Agency’s work in Ukraine to ensure nuclear safety and provide transparency around any disinformation.
“Both leaders agreed on the need to continue to place pressure on Putin’s barbaric regime through continued economic sanctions.
“President Zelensky congratulated the Prime Minister on his appointment and wished him a happy Diwali. The Prime Minister thanked him and said he hoped they would see each other in person soon.”
Writing on Twitter, President Zelensky described it as “an excellent conversation”.
He said: “We agreed to write a new chapter in Ukraine-UK relations but the story is the same – full support in the face of Russian aggression.
“I appreciate PM’s first call to Ukraine. And always grateful for the support of the UK people.”
Rishi Sunak said it was a “privilege” to speak to Ukrainian President Zelensky.
He tweeted: “Both he and the Ukrainian people can count on the UK’s continued solidarity and support. We will always stand with Ukraine.”