Keir Starmer will host Ukraine’s president, Volodymyr Zelenskyy, on Tuesday as the prime minister warns US-Israeli strikes on Iran cannot be allowed to become a “windfall for Putin”.

Zelenskyy’s visit will come on the day of the government deadline for the Russian oligarch Roman Abramovich to pay proceeds from his sale of Chelsea FC to victims of the Ukraine war.

The former Chelsea owner is now expected to face legal action , having insisted that the £2.5bn raised by the sale is his to allocate, including to Russian victims of the war.

The British government warned Abramovich last year he must release the cash, or he could be taken to court. A government source said there was no expectation that Abramovich would pay by the deadline.

On Monday, Abramovich’s lawyers at Kobre & Kim said the cash was still “wholly owned” by Fordstam Ltd, the vehicle through which the billionaire funded Chelsea.

Starmer is likely to face questions over the future of the cash when Zelenskyy arrives in the UK on Tuesday. Both Starmer and the defence secretary, John Healey, expressed firm support for Ukraine on Monday and said they were continuing weapons supplies.

The prime minister said it “was vital that we continue to focus on supporting Ukraine. We cannot allow the war in the Gulf to turn into a windfall for Putin.”

Russia has received €6bn (£5bn) from selling its fossil fuels in the fortnight since the start of the US-Israel war with Iran, data suggests.

Speaking in the Commons, Healey said the flow of weapons to Ukraine was continuing from the UK. “I can confirm today that, over the last month, we have delivered to Ukraine 3,500 drones, 18,000 artillery rounds and 3m rounds of small ammunition,” he said.

“We face two conflicts on two continents, supported by an axis of aggression with similar tactics and similar technologies. I say this to the Ukrainian people on behalf of the UK: we will not forget the war in Europe and our total determination to stand with Ukraine remains steadfast, and we will welcome President Zelenskyy to this country tomorrow.”

Russia’s commodity revenues are a vital component of state revenue to fund its military operations in Ukraine. Last week Donald Trump activated a US waiver for one month to let countries buy up Russian oil without facing sanction. The US has previously applied tariffs to countries such as India for buying Russian oil.

Zelenskyy appeared to push back against Trump’s claim that the US did not need Ukraine’s help on drone defence.

The US had contacted Ukraine “several times” to ask for help for a particular country, or for support for Americans, Zelenskyy said. “All our institutions received these requests, and we responded to them,” he told a briefing, without providing specifics.

Healey has previously said he sees the Russian president, Vladimir Putin’s “hidden hand” behind some of the Iranian tactics and their retaliation with drone and missile attacks against Gulf states. He said the Russian president was benefiting from the surge in oil prices.

“It helps him with a fresh supply of funds for his brutal war in Ukraine,” he said.