US first lady Jill Biden made an unannounced visit to western Ukraine on Sunday, holding a surprise Mother’s Day meeting with the nation’s first lady, Olena Zelensky, as Russia presses its punishing war in the eastern regions.

US president Joe Biden has not visited the country, though he expressed a desire to when he was in Poland this spring, following Russia’s invasion in February, but at that time Russian tanks were advancing on the capital, Kyiv, and he hinted that his security advisers held him back.

Jill Biden traveled under the cloak of secrecy, becoming the latest high-profile American to enter Ukraine during its 10-week-old conflict with Russia.

Russian forces drew back from Kyiv in the weeks after Biden’s trip to Poland, and the return of a greater level of security in the capital prompted visits by House Speaker Nancy Pelosi, days after US secretary of state Antony Blinken and defense secretary Lloyd Austin, and other world leaders, including British prime minister Boris Johnson, had met there with Ukrainian president Volodymyr Zelensky.