Volodymyr Zelensky has said Ukraine will face a deficit of missiles it is using to fight Russia due to the war in the Middle East.
In an exclusive interview with the BBC, the Ukrainian president said Russia's Vladimir Putin wanted a "long war" between the US, Israel and Iran because it would weaken Kyiv, with US resources being directed elsewhere.
Zelensky also claimed that US President Donald Trump was not on "any side" in the war between Russia and Ukraine and did not want to "irritate" Putin.
He urged Trump and Sir Keir Starmer to meet and find common ground, after the US president's repeated criticism of the UK prime minister.
Now in its third week, the conflict in the Middle East has spread across the Gulf with Iran lashing out at neighbouring states in retaliation to the US and Israel's strikes.
Zelensky said he had a "very bad feeling" about the impact of the conflict on the war in Ukraine, saying negotiations towards peace are being "constantly postponed. There is one reason - war in Iran".
He also said the situation was benefiting Putin because it increased energy prices, which was a problem for Ukraine, and meant there could be a "deficit" of missiles.
"For Putin, a long war in Iran is a plus," he said. "In addition to energy prices, it means the depletion of US reserves, and the depletion of air defence manufacturers. So we [Ukraine] have a depletion of resources."
Zelensky said there would "definitely" be a deficit of Patriot missiles which would be "a challenge", saying the question now was "when will all the stockpiles in the Middle East be exhausted".
"America produces 60-65 missiles per month. Imagine, 65 missiles per month is is about 700-800 missiles per year, produced each year," he said. "And on the first day in the Middle East war, 803 missiles were used."
Zelensky also spoke about his US counterpart's position on the Ukraine war, saying that Trump wanted to be a negotiator rather than take any side in Ukraine's war against Russia's illegal invasion.
The Ukrainian president said he thought Trump "wants to finish this war" but added that the US president and his advisers had chosen a strategy of close dialogue with Putin, and "not to irritate him because Europe irritated him and Putin does not want to talk to Europe".
The war ignited by US and Israeli strikes on Iran has spilled into a diplomatic row after Trump's reprimanding of the Nato allies and Sir Keir's supposed lack of military action. Zelensky warned against division among western leaders.
Speaking to the BBC after talks with Sir Keir, the Ukrainian president said that while he would not tell Trump what to do, the pair should meet to "re-load the relationship".
"I would really like President Trump to meet with Starmer... so that they have a common position," he said.
In his latest attack on Tuesday, Trump branded Starmer "no Winston Churchill" and said that while he thinks the UK prime minister is a "nice man" he is "disappointed".
Sir Keir's response held firm, insisting the UK will not be drawn into a wider war, with Downing Street reiterating an "enduring" US-UK relationship.
Sir Keir welcomed Zelensky to Downing Street on Tuesday - the latest stop on the Ukrainian leader's tour of European capital cities.
Zelensky visited Paris last week and travels to Madrid on Wednesday. The visits come as the Middle East conflict overshadows Ukraine's four-year fight against Russia's full-scale invasion.
"I think it's really important that we are clear that the focus must remain on Ukraine," said Sir Keir.
As part of Zelensky's visit to London, the Ukrainian leader addressed MPs in Parliament.
"The regimes in Russia and Iran are brothers in hatred and that is why they are brothers in weapons," Zelensky said. "And we want regimes built on hatred, to never, never win in anything. And we want no such regime to threaten Europe or our partners."
Among those in the audience in a packed Westminster committee room were Sir Keir, Nato Secretary-General Mark Rutte, Defence Secretary John Healey and leaders of opposition parties.
Source: BBC