Andy Burnham has promised to keep up the pressure on Russia despite Moscow’s “outrageous threats”, on his first official visit to Ukraine as UK prime minister.

Burnham met Ukrainian President Volodymyr Zelensky and chaired his first meeting of the “coalition of the willing”, set up by the UK and France under his predecessor Sir Keir Starmer.

He said the coalition was “doing everything we can” while urging the US Congress to “ratchet up” economic pressure on Russia.

The government is set to hand over blueprints for British-made components for the Scalp missile, a French version of the UK’s Storm Shadow cruise missile – allowing Ukraine to produce the weapon domestically.

During the meeting with France and Ukraine, Burnham said allies were doing “everything we can” to “dig into our own stocks and help others dig into their stocks” of air defences to protect Ukraine.

“This is the moment to keep up the pressure on Russia, the moment to squeeze their ability to fund this illegal war,” Burnham said, praising the “strength” of the Ukrainian people.

“Ukraine has been Europe’s protector, not a drain on our security but the front line in keeping Europe safe.”

It comes after Kremlin spokesman Dmitry Peskov criticised the UK’s decision to share the missile blueprints. Peskov said it prevented “even the slightest progress” towards achieving peace.

He told reporters on Monday that the Russian military was already gathering data to locate any missile production sites to destroy them.

“Britain is involved in this war on the side of the Kyiv regime. Britain methodically and regularly adds fuel to the fire,” he added.

In response, Burnham said: “Who started the fire? That’s the question, isn’t it.”

He added the issue of missile interceptors would be the main topic at the coalition of the willing meeting.

Burnham has been reaffirming the UK’s backing for Kyiv in the wake of escalating Russian strikes on Ukraine in recent weeks – including one on a shopping centre on Friday that killed at least 16 people.

In a joint statement after the meeting, Burham and co-chairs French President Emmanuel Macron and German Chancellor Friedrich Merz said the group would aim to strength Kyiv’s air defences “as a matter or urgenty priority”.

They also condemned Moscow’s “systemic and escalating strikes against Ukraine’s cities, critical infrastructure and civilians” and pledged to “constrain Russia’s war chest through sanctions and actions against the “shadow fleet”.

It came as the European Union said it had released an 6.1bn euros (£5.2bn) in military aid for Ukraine to boost its air defences. The finance is part of a wider 90bn euros loan from the EU to Ukraine.

On Monday morning the prime minister laid flowers at the graves of Ukrainian soldiers during a service at the National Military Memorial Cemetery.

He also accepted an award from Zelensky on behalf of the British people recognising the UK’s support for Ukraine during an independence day event outside the St Sofia cathedral in Kyiv.

Ahead of his visit, Burnham said: “On Ukraine’s 35th anniversary of independence, the Ukrainian people should be in no doubt: the UK is behind you today and for as long as it takes.

“I am proud of the contribution our country has made to Ukraine and I want the Ukrainian people to hear it directly from me that our support will not waver. After all, Ukraine’s security is our security.”

He said the friendship Ukraine shared with the UK would “long outlast Russia’s illegal war”, adding: “Russia should be in no doubt of our resolve. We will not back down until there is a just and lasting peace.”

It comes after Moscow warned of “consequences” over the use of British drones by Ukraine in its recent ramping up of strikes on Russian infrastructure.

Kyiv has stepped up long-range attacks on Moscow and other Russian regions, targeting oil refineries and warehouses of the country’s largest online retailer, Wildberries.

The government is allowing UK defence company MBDA to declassify information on UK components for the Scalp missile.

The long-range missile weighs 1,300kg and is 16.7ft (5.10m) in length. It is capable of hitting targets around 150 miles into Russia – not as far as Ukraine’s deep strike drone capability but it is a significant step in showing the willingness of international partners to share weapons technology.

The maker describes them as designed to hit pre-planned, stationary targets. It can be used day and night in all weather, and has advanced navigation systems.

MBDA adds that it is in service with the Royal Air Force, the French Air Force, Italian Air Force and has been used in Iraq, Syria and Libya.

Ukraine hopes it can also be given more Patriot interceptor missiles, with Zelensky again asking for more of the weapon, which are used to combat Russia’s ballistic missiles.

On Sunday, he said they have requested 360 of the missiles, but are “working with countries on additional options”.

Ukraine has been relying on American supplies of the Patriots, but its stockpiles are running low due to the war in Iran, leaving Ukraine vulnerable to Russian attacks.

While the Scalp missile does not intercept enemy attacks like the Patriots, Defence Minister Luke Pollard told BBC Breakfast they were sharing its blueprints so Ukraine could “defend against this illegal invasion that’s now killed so many people”.

“It’s not just the front lines, it’s shopping centres, it’s housing that’s being targeted by Russia in their illegal war and that’s why we have said and we will continue to make sure our actions follow it that we will support Ukraine for as long as it takes,” he added.

Pollard said Ukraine is in need of a variety of weapons, which is why the UK is supplying other air defence assets to take down Russian cruise missiles, and counter-drone measures.

The Russian embassy in the UK has accused Britain of “deliberately opting for an escalation of the Ukraine crisis”, saying “the deeper its involvement in the conflict… the higher the price it will pay”.

In response, Burnham said last week: “We are not fair-weather friends, we will be there in Ukraine’s hour of need and that won’t change.”

Asked on Tuesday about the Russian threat, Burnham maintained the UK was “providing support so that Ukraine can defend itself and that’s been the British position all the way through this conflict, by previous prime ministers – it remains the case with me”.

The visit comes as Russia confirmed its ambassador to the UK, Andrei Kelin, had left his post in London in recent weeks.

The Kremlin is yet to put forward a replacement but Russia’s embassy to the UK told the BBC it did not reflect an intention to downgrade diplomatic relations between the two nations.

Deadly exchanges between Russia and Ukraine continued overnight, with two children killed and seven injured when Ukrainian drone debris hit a private children’s centre in Russia, local authorities say.

A warehouse belonging to online retailer Ozon was also set on fire, two days after Ukraine said it would target the company for selling dual use items that could be used by the military.

It was at the third night in the row that Ozon’s warehouses had been targeted, with the company confirming on Saturday that a logistics centre in the Samara region had been hit and a warehouse in Orenburg on Sunday.

Three people were also killed in a Russian attack on the north-eastern Ukrainian city of Kharkiv, regional Governor Oleh Syniehubov said.

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