Zelenskiy urged Ukraine's allies not to forget about his country during a Middle East war that has also revived Russia's ailing economy through increased oil revenue and could soon limit Ukrainian access to allied air defence systems that are needed in the Middle East.
"The regimes in Russia and Iran are brothers in hatred and that is why they are brothers in weapons," Zelenskyy told MPs in the United Kingdom parliament.
"And we want regimes built on hatred to never, never win in anything".
Holding talks with Zelenskiy at 10 Downing Street, Starmer said "(Russian President Vladimir) Putin can't be the one who benefits from the conflict in Iran, whether that's oil prices or the dropping of sanctions".
The meeting came days after the US temporarily waived some Russian oil sanctions in a bid to ease pressure on global supplies triggered by the war in the Middle East, which was sparked by the joint US-Israeli strikes on Iran starting February 28.
Zelenskiy and some other European leaders criticized the US move to ease sanctions, saying it would provide a windfall for Russia to keep up its attacks on Ukraine.
Zelenskiy also met with King Charles III at Buckingham Palace before addressing dozens of members of the House of Commons and the House of Lords in parliament.
He told them that other countries could learn from Ukraine's agile adoption of technology, including drones and AI, for defence.
"The fact we got through this winter, which Russia tried to make deadly for all our families, shows that our solutions work," Zelenskiy said.
Zelenskiy said the London talks, also attended by NATO Secretary-General Mark Rutte, would assess energy security after Russia hammered Ukraine's power grid over the winter as well as the battlefield situation.
