A day after hosting a forum of European leaders at Blenheim Palace, Starmer pressed on with his bid to raise Britain's role in international affairs by inviting Zelenskiy to address his cabinet of top ministers.
The last foreign leader to do so was US president Bill Clinton in 1997, Starmer's office said.
Zelenskiy renewed his call for Western allies to allow long-range strikes on Russia, saying Britain should try to convince its partners, which have taken varying approaches to how Ukraine can use weapons they supply, to remove the limits on their use.
"Right now we are missing the main answer to this question and that is our long-range capability," Zelenskiy said at the beginning of the meeting in Downing Street.
Keir Starmer told Volodymyr Zelenskiy that Britain would speed up delivery of vital aid to Ukraine. (AP PHOTO)
"Please convince the other partners to remove the limits."
Starmer told Zelenskiy Britain would speed up delivery of vital aid to Ukraine after his defence minister said earlier in July the deliveries promised by the former Conservative government would be delivered within 100 days.
"Ukraine is, and always will be, at the heart of this government's agenda and so it is only fitting that President Zelenskiy will make a historic address to my cabinet," Starmer said in a statement before the meeting.
Britain has been a vocal supporter of Ukraine since Russia's full-scale invasion in 2022, and Starmer swiftly reaffirmed London's commitment to Kyiv after winning a landslide election earlier this month, telling Zelenskiy at NATO while there was a change of government, there was "no change of approach".
He said on Thursday that Britain would pursue a new plan to try to disrupt Russia's attempts to evade shipping sanctions.
On Thursday, Britain announced sanctions on 11 vessels used to transport Russian oil.
The new measures against Russia's so-called "shadow fleet" include plans to share data on the network of the often older tankers used in shipping Russian oil, so that individual vessels can be identified and action taken against them.
He also unveiled the Defence Export Support Treaty that will enable Ukraine to draw on Stg3.5 billion of export finance, to fire up both countries' defence industrial bases and boost production.
Starmer, at NATO last week, re-committed to a pledge by his predecessor, Conservative Rishi Sunak, to deliver Stg3 billion a year ($A6.8 billion) of military support to Ukraine until 2030-31 and beyond if needed.
