The Foreign Secretary has announced a package of "hands-on" support to help Ukraine – in which the UK will send six armoured vehicles and 35 more emergency vehicles, including 24 ambulances to the country.
James Cleverly met Volodymyr Zelensky during a visit to Kyiv, just days after Prime Minister Rishi Sunak also travelled to the Ukrainian capital
He promised Ukraine's president the UK will commit "action – not just words" in its support of the war-torn nation.
Mr Cleverly said the UK intends to keep its pledge to offer "concrete" assistance, as words alone "won't keep the lights on" or "defend against Russian missiles".
The Foreign Secretary shared a photo of his meeting with Mr Zelensky, addressing him directly.
"President Zelensky, the UK is supporting you with action – not just words," he wrote.
"I made you that promise today. The UK intends to keep it."
Mr Cleverly announced the practical support as Ukraine's power grid and other critical infrastructure has been hit by Russian strikes, causing blackouts and leaving millions without heat, power or water as temperatures plummet.
Thanking Ukrainian foreign affairs minister Dmytro Kuleba for welcoming him to the country, and sharing a photo of their meeting, he insisted words alone "won't keep the lights on" or "defend against Russian missiles".
"The UK isn't just talking about Ukraine, we're providing concrete support for the defence of Ukraine," he tweeted.
"Thank you Dmytro Kuleba for welcoming me to Kyiv."
The Foreign Secretary also announced a further £3m for the rebuilding of local infrastructure including schools and shelters, as well as additional funding to support survivors of sexual assault.
Mr Cleverly said: "As winter sets in, Russia is continuing to try and break Ukrainian resolve through its brutal attacks on civilians, hospitals and energy infrastructure. Russia will fail.
"The UK stands shoulder to shoulder with Ukraine. I have today announced a package of hands-on support for our Ukrainian friends in their fight, from ambulances to crucial support for survivors of the sexual violence carried out by the Russian military.
"I've seen here first-hand how the UK's efforts are helping brave citizens to resist and rebuild. Our support will continue for as long as it takes for this remarkable country to recover."
Rishi Sunak's visit to Kyiv last Saturday was accompanied by the announcement of a £50m package of defence aid comprising 125 anti-aircraft guns and technology to help Ukraine counter Iranian-supplied drones, including radars and anti-drone equipment.
The Prime Minister said it was "deeply humbling" to be in the Ukrainian capital and that he was "proud" of how the UK had backed the country since Moscow's invasion began.