Sir Keir Starmer has arrived in kyiv to sign what Downing Street calls a “historic 100-year partnership” with Ukraine.
The deal would formalize the economic and military support already promised to the country and deliver more.
It is the prime minister’s first visit to the country since taking office last summer, in a show of support for Ukraine days before Donald Trump returns to the White House.
Ukrainian President Volodymyr Zelensky wants to discuss firm security guarantees from key allies such as the United Kingdom, fearing that a new U.S. administration could begin pushing Ukraine to make peace with Russia.
Unlike other prime ministers who rushed to kyiv, Sir Keir took his time getting there, but after six months in office he came to Ukraine pledging long-term support against what he calls the “illegal and barbaric invasion” of Russia.
He was welcomed at kyiv railway station by the UK Ambassador to Ukraine, Martin Harris, and the Ukrainian envoy to London, Valerii Zaluzhnyi.
The highlight of the visit will be the signing of the 100-year partnership agreement, Zuluzhnyi said, which will cover areas from science to culture, with a particular focus on security.
Speaking during his trip to the country, Sir Keir said: “It’s not just about the here and now, it’s also about investing in our two countries for the next century.”
“[Russian President Vladimir] Putin’s ambition to wrest Ukraine from its closest partners has proven to be a monumental strategic failure. On the contrary, we are closer than ever, and this partnership will take that friendship to the next level,” he added.
Trump’s pick for secretary of state, Marco Rubio, said earlier this week that both countries would have to make concessions to end the war.
Thursday’s announcement includes more military and economic aid to prove it, as well as increased military collaboration in maritime security, drone technology and health care.
Zelensky has previously said he is looking to the United Kingdom for help in securing security guarantees to deter future attacks.
Joining NATO is high on its wish list, but Ukraine also wants its allies to send peacekeepers to the country if the fighting stops, to patrol the current front line which could become a buffer zone in any peace agreement.
Before the visit, Zelensky said it was a topic he would discuss with the prime minister.
It builds on the UK’s already £12.8 billion of support for Ukraine. The country has also already pledged £3bn in military aid each year “for as long as it takes”.
Ukraine has previously used UK-supplied Storm Shadow missiles to attack Russian military installations far from the border.
Their arrival late last year was welcomed by kyiv and criticized by Moscow.
The partnership, consisting of a treaty and a political declaration, must be presented to Parliament in the coming weeks.
Plans for this began under the previous Conservative government.
Sir Keir previously visited Ukraine when he was leader of the opposition in 2023 and has hosted President Zelensky twice at Downing Street since taking office.
Additional reporting by Alex Smith.