Prime Minister Keir Starmer signaled continued solidarity, with further U.S. support in question under a second Trump administration.
Prime Minister Keir Starmer of Britain met with President Volodymyr Zelensky of Ukraine in Kyiv on Thursday, a show of solidarity four days before the inauguration of Donald J. Trump.
The trip to Ukraine, Mr. Starmer’s first since he became prime minister over the summer, comes amid a flurry of diplomacy between Kyiv and its European allies, who are watching to see whether Mr. Trump maintains American support for Ukraine in the war against Russia.
Britain is the third-largest provider of military aid to Ukraine, after the United States and Germany, and on Thursday Mr. Starmer and Mr. Zelensky signed a “100-year partnership” between their two countries.
“We have reached a new level — this is more than a strategic relationship,” Mr. Zelensky told a news conference that the two leaders held. Mr. Starmer said that Britain would provide more military aid to Ukraine this year “than ever before.”
The partnership agreement will include a particular focus on maritime security and promises to strengthen collaboration on technology, health care and education. It follows a narrower security agreement signed a year ago in response to the invasion that President Vladimir V. Putin of Russia ordered in 2022.
“Putin’s ambition to wrench Ukraine away from its closest partners has been a monumental strategic failure,” Mr. Starmer said in a statement. “Instead, we are closer than ever.”