US President Joe Biden and first lady Jill Biden have welcomed Ukraine’s first lady to the White House for a visit ahead of her address to Congress on Wednesday.

Olena Zelenska, the wife of Ukraine President Volodymyr Zelensky, embraced Ms Biden on Tuesday and received flowers from the president, who met her vehicle outside.

Afterwards, the two women and delegations from both countries sat down for a meeting in the White House Blue Room.

Ms Biden had made a surprise visit to Ukraine, which Russia invaded on February 24, in May, visiting her counterpart and a school that was sheltering displaced Ukrainians.

Mr Zelensky later said he expected “significant results” from his wife’s meetings in Washington.

Her tasks included increasing US support for Ukraine, obtaining additional support to “protect people from Russian terror” and boosting humanitarian assistance, he said in a late-night video address.

Mr Zelensky said the speech to Congress would be important, adding “I strongly believe it will be heard by those people responsible for making decisions in the United States”.

Russia calls its action in Ukraine a “special military operation” to ensure its own security. Mr Zelensky has led his country in standing up to Moscow.

-AAP