The US will support Ukraine in its fight against Russia “until victory is won”, House Speaker Nancy Pelosi said after a visit to Kyiv.
The Californian Democrat led a congressional delegation to the Ukrainian capital to meet President Volodymyr Zelenskyy before heading to Poland for talks with officials.
Ms Pelosi is the most senior American politician to visit Ukraine since Russia invaded in February.
“Our delegation travelled to Kyiv to send an unmistakable and resounding message to the entire world: America stands firmly with Ukraine,” a statement by Ms Pelosi released on Sunday said.
The unannounced visit to Kyiv on Saturday was publicised only after she had left Ukraine. It marks a show of continuing support for the country’s struggle against Moscow.
Footage released by President Zelenskyy’s office showed Ms Pelosi and other US politicians in the city. In video later released by Ms Pelosi’s office, the two thanked each other for their support in the war.
“You all are welcome. We’ll win and we’ll win together,” Mr Zelenskyy told the delegation.
Ms Pelosi said: “We are here until victory is won.”
She told Mr Zelenskyy the visit was 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,” she said.
Mr Zelenskyy said he was “very grateful for this powerful signal of support". The US "is a leader in strong support for Ukraine during the war against the aggression of the Russian Federation", he said.
The US delegation included Democratic representatives Gregory Meeks, Adam Schiff, Jim McGovern, Jason Crow, Barbara Lee and Bill Keating.
The delegation later travelled to Warsaw to meet Polish President Andrzej Duda and other senior officials.