British Prime Minister Keir Starmer arrived in Ukraine Thursday with a pledge to help guarantee the country’s security for a century, days before Donald Trump is sworn in as U.S. president.

British Prime Minister Keir Starmer pledged on Thursday to work with Ukraine and allies to offer Kyiv robust security guarantees if a ceasefire is negotiated with Russia, offering more support to President Volodymyr Zelenskiy with a 100-year partnership deal.

Struck by the “grim reminder” of war while visiting a burns hospital unit in Kyiv earlier today, the prime minister promised the UK would “play its full part” in guaranteeing Ukraine’s security. The Sheffield-made guns will be delivered to Ukraine’s military over the next few weeks as part of this deal, Sir Keir said.