UK Foreign Secretary James Cleverly announced new aid for Ukraine on a visit to Kyiv on Friday, including ambulances and support for victims of sexual violence by Russian soldiers.
After meeting President Volodymyr Zelensky, Cleverly tweeted: "President @ZelenskyyUa, the UK is supporting you with action -- not just words.
"I made you that promise today. The UK intends to keep it," he said, after Prime Minister Rishi Sunak used a visit last weekend to the Ukrainian capital to set out a new package of military aid worth £50 million ($60 million).
Zelensky hailed the visit by Britain's most senior diplomat just days after the latest Russian barrage of missiles against Ukraine's energy grid leading to widespread blackouts.
"Your visit is taking place against the background of a large-scale Russian missile attack, which left all of Ukraine without electricity and water. But that didn't stop you. Thank you," Zelensky's press service quoted him as saying.
The package announced by Cleverly includes 24 ambulances and six armoured vehicles, according to the foreign office.
He unveiled a further £3 million towards rebuilding infrastructure such as schools and shelters, and extra funding to support "survivors of the sexual violence carried out by the Russian military", the ministry added.
"As winter sets in, Russia is continuing to try and break Ukrainian resolve through its brutal attacks on civilians, hospitals and energy infrastructure," Cleverly said.
"Russia will fail," he said, vowing UK support "will continue for as long as it takes".
The UK government said it was also committing £5 million to a Ukraine-led initiative, delivered through the UN World Food Programme, to ship grain to countries most at risk of famine, including Sudan and Yemen.
"Global food security is in all our interests," Environment Secretary Therese Coffey said.
"And helping Ukraine's farmers and agricultural sector to continue producing and exporting food in these most difficult of circumstances is vital for that security," she said.
On his visit, Sunak promised 125 anti-aircraft guns and equipment to help Ukraine counter Iranian-supplied drones, along with cold-weather winter kit to its armed forces.
On Wednesday, Britain's defence ministry said it was sending helicopters to Ukraine for the first time since Russia's invasion -- three Sea Kings, along with an additional 10,000 artillery rounds.