The UK will continue to “stand steadfastly by” Ukraine throughout 2024, the Prime Minister has told Volodymyr Zelensky.

Rishi Sunak also discussed providing “further deliveries of lethal aid” to Kyiv with Ukrainian president Mr Zelensky as the two leaders spoke in a phone call on Tuesday.

In a readout of the call between the leaders, a Downing Street spokeswoman said: “Prime Minister Rishi Sunak spoke to Ukrainian president Volodymyr Zelensky today.

“He offered his condolences to all those Ukrainians killed and injured in barbaric Russian airstrikes over the Christmas period.”

Kremlin forces killed at least five people and more than 100 were injured in the bombardment of Kyiv and Kharkiv, Ukraine’s two largest cities, the Ukrainian government said on Tuesday.

The Downing Street spokeswoman continued: “The Prime Minister said the UK would continue to stand steadfastly by Ukraine as they fight aggression and occupation, throughout 2024 and into the future.

“The leaders discussed recent developments in the conflict, including progress in the Black Sea and the success of the Ukrainian air defence, bolstered by UK-supplied ground-to-air missiles.

“The Prime Minister set out ongoing UK work to provide military and diplomatic support to Ukraine, including through further deliveries of lethal aid, support for President Zelensky’s peace plan and a long-term security framework.”

The UK has committed £4.6 billion of military spending towards Ukraine’s defence against the Russian invasion since 2022, with £2.3 billion provided in 2022, and matched in 2023.

Ministers have come under pressure in recent months to reveal when they will provide further military funding for 2024.

Foreign Secretary Lord Cameron told peers in December that the UK is “absolutely committed to continuing to support Ukraine at the level or even ahead of what we have done”.

Lord Cameron spoke to his US counterpart, Antony Blinken, on Tuesday, discussing continuing support for Ukraine among other global crises in Gaza and the Red Sea.

A spokesperson for the Foreign Office said: “The Foreign Secretary and secretary of state discussed Russia’s deplorable air strikes against Odesa, Lviv, Dnipro, Kharkiv and Kyiv over the new year period, and their steadfast commitment to supporting Ukraine this year.”