• The meeting was held to "confirm continued UK support" for Ukraine in the ongoing war against Russia, a No 10 spokesperson said.
• Ukraine has been requesting assistance from Western nations in recent months amid intense Russian aerial attacks on Kyiv and across the country.
British Prime Minister Rishi Sunak has met Ukraine's President Volodymyr Zelensky in his first visit to Kyiv since taking office.
The meeting was held to "confirm continued UK support" for Ukraine, a No 10 spokesperson said.
"We discussed the most important issues both for our countries and for global security," Mr Zelensky wrote on Telegram following the meeting.
"We are stronger and we will achieve the desired results," he added.
Mr Sunak - who took office last month - said it was "deeply humbling" to be in Kyiv and pledged that the UK would continue to stand by Ukrainians in their fight.
During the meeting with Mr Zelensky, he said the UK would provide a major new package of air defence to help protect Ukrainian civilians and the country's national infrastructure from Russian strikes.
Ukraine has been requesting assistance from Western nations in recent months amid intense Russian aerial attacks on Kyiv and across the country.
The £50 million package of defence aid comprises 125 anti-aircraft guns and technology to counter deadly Iranian-supplied drones, including dozens of radars and anti-drone electronic warfare capability.
It follows more than 1,000 new anti-air missiles announced by the UK's Defence Secretary Ben Wallace earlier this month.
Earlier in the week Russia hit Ukraine with one of its biggest barrages of missiles yet, days after its troops were forced to withdraw from Kherson.
Kyiv was hit and there were strikes across the country, from Lviv in the west to Chernihiv in the north.
That attack coincided with the G20 summit in Bali where, in a virtual speech, Mr Zelensky said he was "convinced now is the time when the Russian destructive war must and can be stopped".
Mr Sunak announced the UK will also increase the training offer to Ukraine's armed forces, sending expert army medics and engineers to the region to offer specialised support.
While in Kyiv, the UK prime minister laid flowers at a memorial for the war dead and lit a candle at a memorial for victims of the Holodomor famine, before meeting emergency workers at a fire station. Mr Sunak also saw captured Iranian-made drones which have been used to target and bomb Ukrainian civilians in recent months.
"I am proud of how the UK stood with Ukraine from the very beginning. And I am here today to say the UK and our allies will continue to stand with Ukraine, as it fights to end this barbarous war and deliver a just peace," Mr Sunak said.
"While Ukraine's armed forces succeed in pushing back Russian forces on the ground, civilians are being brutally bombarded from the air. We are today providing new air defence, including anti-aircraft guns, radar and anti-drone equipment, and stepping up humanitarian support for the cold, hard winter ahead," he added.