US House Speaker Nancy Pelosi has met with Ukrainian President Volodymyr Zelensky in Kyiv, becoming the highest-ranking American leader to visit Ukraine since the start of the war.
Her visit marks a major show of continuing support for the country's fight against Russia’s invasion.
"Our delegation travelled to Kyiv to send an unmistakable and resounding message to the entire world: America stands firmly with Ukraine," she said in a statement released on Sunday.
Footage released by Mr Zelensky's office showed Ms Pelosi and other US legislators in Kyiv.
"You all are welcome," Mr Zelensky told the delegation.
Ms Pelosi told the Ukrainian leader: "We believe that we are visiting you to say thank you for your fight for freedom.
"We are on a frontier of freedom and your fight is a fight for everyone. Our commitment is to be there for you until the fight is done."
The visit was not previously announced.
Ms Pelosi said the delegation will continue its trip in south-east Poland and the capital, Warsaw, to meet President Andrzej Duda and other senior officials. Poland has received more than three million refugees from Ukraine since Russia launched its war on February 24.
"We look forward to thanking our Polish allies for their dedication and humanitarian efforts," she said.