Rishi Sunak has joined other world leaders in reaffirming support for Ukraine on the second anniversary of Russia’s invasion, vowing to back Kyiv “until they prevail”.

The Prime Minister said “tyranny will never triumph” as President Volodymyr Zelensky’s troops defend the country against an emboldened Moscow.

The UK has pledged to invest £245 million in producing artillery shells for Ukraine and £8.5 million in humanitarian funding as the conflict enters its third year.

We are prepared to do whatever it takes, for as long as it takes, until they prevail

Saturday marks two years since the Kremlin launched its attack on Ukraine, starting the biggest incursion in a European country since the Second World War.

Mr Sunak, who visited Kyiv last month to sign a new security agreement and announce an increase in military funding for the country, said on Friday: “When (Russian President Vladimir) Putin launched his illegal invasion two years ago, the free world was united in its response.

“We stood together behind Ukraine. And on this grim anniversary, we must renew our determination.

“I was in Kyiv just a few weeks ago and I met wounded Ukrainian soldiers. Each harrowing story was a reminder of Ukraine’s courage in the face of terrible suffering.

“It was a reminder of the price they are paying not only to defend their country against a completely unjustified invasion, but also to defend the very principles of freedom, sovereignty and the rule of law on which we all depend.”

The UK and our allies will stand in solidarity with them until their day of victory

He added: “This is the moment to show that tyranny will never triumph and to say once again that we will stand with Ukraine today and tomorrow.”

In a rare joint post on social media, Mr Sunak teamed up with former prime minister Boris Johnson, during whose premiership the war started, to express solidarity with Mr Zelensky.

“Britain was with you then and we’re with you now – for as long as it takes. Slava Ukraini,” they said.

Labour leader Sir Keir Starmer, who hopes to enter Number 10 after the general election this year, said Britain would always support Ukraine “no matter who is in power in this country” and added that Mr Putin’s “cowardice and barbarity” will not prevail.

Sir Keir said: “The resistance of the Ukrainian people has inspired and humbled the world. The UK and our allies will stand in solidarity with them until their day of victory.

“We will not waver. We will not abandon them. We will not be divided in the face of tyranny or oppression.

“We look together to the day when Ukraine secures justice and liberty in their rightful homeland, when Ukrainians can return home and rebuild their great country, and live peacefully, freely and proudly.”

European countries are struggling to find enough weapons and ammunition to send to Kyiv, and US help worth 60 billion dollars (£47 billon) is stalled over political differences in Washington.

Ukrainian forces withdrew from the strategic eastern city of Avdiivka at the weekend, where they had battled a fierce Russian assault for four months despite being heavily outnumbered and outgunned.

Kyiv has kept up strikes behind the front line but moved to a defensive posture amid critical shortages on the battlefield.

Speaking to BBC Breakfast, Defence Secretary Grant Shapps was asked whether the funding package announced on Saturday was enough.

“That £245 million is just a fraction of the £2.5 billion we’re giving in direct aid and military assistance this year… but ammunition is the thing that Ukraine desperately needs at the moment,” he said.

Mr Shapps echoed concerns raised by Foreign Secretary Lord Cameron over the progress of the US funding package through Congress, where it faces an uphill battle as hardline Republicans in the House of Representatives oppose the legislation.

But he said politicians across the political spectrum in the UK are united in its support for Kyiv. “Parliament can be divided over all sorts of things but we are not in our support for Ukraine,” he said.

It comes after Lord Cameron used his speech at the UN General Assembly in New York to warn allies against “fatigue” and “compromise” over the war.

In some of his strongest language yet, he denounced Mr Putin and his inner circle for behaving like “Nazis” and thinking they could invade a country and “the world would look away”.

The Foreign Secretary told reporters during the visit that defending Ukraine is “fundamentally about US security too” in a fresh appeal to members of Congress to pass the aid bill.

Western leaders descended on Kyiv this weekend in a show of support for Mr Zelensky.

European Commission president Ursula von der Leyen travelled overnight to the capital by train along with Italian premier Giorgia Meloni, Belgian Prime Minister Alexander De Croo and Canadian Prime Minister Justin Trudeau.

They arrived shortly after a Russian drone attack struck a residential building in the southern city of Odesa, killing at least one person.

“More than ever we stand firmly by Ukraine. Financially, economically, militarily, morally. Until the country is finally free,” Ms von der Leyen wrote on social media.