Andy Burnham has said the UK is “with Ukraine 100%” as Volodymyr Zelensky became the prime minister’s first international visitor since entering No 10.

Burnham said the visit of the Ukrainian president was designed to “send a very clear message” about the UK’s continued support.

“To put it simply, Volodymyr, I want you to know that we’ve got your back, you can count on me and you can count on us. You can count on the UK for as long as it takes,” he said at a naval base in Portsmouth on Monday.

Zelensky, meanwhile, said Ukraine’s relationship with the UK was “stronger than ever”.

Addressing Zelensky, Burnham said: “I am personally with you 100%, Mr President, and I will honour every commitment this country has made to Ukraine in full.”

Burnham added that he intended to visit Ukraine “soon” following the “very warm meeting” between the pair.

The PM also announced the sharing of the intellectual property behind the UK’s new “Stone Cloak” electronic warfare system, enabling Ukraine to produce the technology at scale.

Burnham said: “It will help them to hit their targets and help save Ukrainian lives.”

The Stone Cloak jammers are the size of a tablet computer and are designed to block the detection of any drones they are fitted to.

The Ministry of Defence has already given thousands of the devices to Ukrainian forces to bolster their drone operations.

Downing Street said that following its deployment in Ukraine, the technology will be built into the UK’s next generation of long-range weapons.

It said this would include Project Brakestop, a government programme to develop low-cost cruise missiles – self-propelled guided weapons that fly like normal aircraft for much of their flight.

During Monday’s visit, the two leaders also met more than 200 Ukrainian military personnel who have spent the last three weeks taking part in a maritime exercise in the UK.

Exercise Sea Breeze is aimed at strengthening warfighting capabilities and counter-mine measures in the Black Sea.

Burnham also said the UK would support Ukraine to get a “full and unconditional ceasefire”.

“We will keep up the pressure, pushing for a ceasefire and a resumption of negotiations which must have Ukraine at the table and include a strong voice for Europe too.”

Britain’s backing of Ukraine has been constant since Russia’s invasion four years ago, and the UK has committed £25bn in funding, external for the country’s warfighting efforts.

In one of his first calls after becoming prime minister last Monday, Burnham spoke to Zelensky and invited him to visit the UK “at the earliest opportunity”.

Zelensky wrote on X shortly afterwards: “I truly appreciate that the support for Ukraine and our people will remain steadfast.”

Burnham’s predecessor, Sir Keir Starmer, visited Kyiv on his final full day as Labour leader.

During that trip, he announced fresh funding worth £255m (€300m) for Ukraine’s fight against Russia and was awarded Ukraine’s Order of Freedom.

Asked if he was concerned about changes of leadership in Britain, and in France next year, Zelensky said: “Of course I’m afraid of changes, of course we are afraid because we are in the war each day.

“But again the priority is the relation between nations, not just between just people. I’m sure that these relations will not change, or we have to do our best not to lose such very good relations.”

He added: “I hope we will never lose strong relations with the UK during or after the war.” Sir Keir replied: “You won’t.”

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