Kiev: US First Lady Jill Biden arrived in Ukraine on Monday as Washington announced further sanctions on Moscow.
Jill Biden met with Ukraine's First Lady Olina Zelensky, the wife of President Vladimir Zelensky.
The two first ladies met at a school in the border town of Uzhhorod.
It was Mrs Zelensky's first appearance in public since the Russian invasion of Ukraine began on 24 February.
The US imposed new sanctions - including visa curbs on 2,600 Russian and Belarusian individuals - in response to the Russian invasion.
Three Russian TV stations and executives from Gazprombank were also sanctioned by Washington.
Meanwhile, G7 leaders said they were committed to phasing out or banning Russian oil.
The meeting between the two first ladies took place at a school which is currently being used as a temporary shelter for displaced people.
Mrs Biden said she wanted "to show that the people of the United States stand with the people of Ukraine", adding that the war - now in its third month - had been "brutal" and had to stop.
Mrs Zelenska said it had been a "courageous act" to visit Ukraine while it was at war.
She added that the visit, on Mother's Day in Ukraine and in the US, was very symbolic.
"We feel your love and support during such an important day."
The two women later sat down and played with some of the dozens of children who are currently housed at the school, making tissue paper bears - the symbol of the local province.