Ukraine’s President Volodymyr Zelensky is planning to visit Washington on Wednesday and may meet US President Joe Biden, reports say.
It would be his first foreign trip since the Russian invasion in February.
Mr Zelensky could also address Congress, unnamed officials told US media. There is no official confirmation of the visit or the plans.
A visit would be fraught with security concerns – meaning plans could likely change at short notice.
In a letter on Tuesday, Democratic House Speaker Nancy Pelosi urged members of Congress to be in attendance on Wednesday night.
“Please be present for a very special focus on democracy,” she wrote, without giving further details.
Mr Zelensky regularly hosts foreign leaders in the capital, Kyiv, and has visited troops around Ukraine. He made an unannounced visit to the front-line city of Bakhmut on Tuesday.
The Ukrainian president has also spoken frequently to world leaders over the telephone and by video call – often from his office in Kyiv.
But an unannounced visit to a foreign country would mark a first since the war began, and also signal the importance of Ukraine’s relationship with the US which has played a leading role in providing military support.