Ukraine's President Volodymyr Zelensky plans to visit Washington today in his first trip abroad since Russia invaded his country on 24 February, US media reported.
Mr Zelensky is planning to visit the White House as President Joe Biden is expected to announce a new arms package for Kyiv including Patriot missiles, crucial to defending Ukraine against Russian missile and drone barrages, the reports said.
Mr Zelensky could also address the US Congress, which is poised to pass a new budget bill with $44.9bn in fresh aid for Ukraine.
House Speaker Nancy Pelosi told members of Congress in a letter today that they should be physically present for a session tomorrow night.
"Please be present for a very special focus on democracy Wednesday night," she wrote, without explanation.
Mr Zelensky, who has led his country without rest for 10 months of brutal war with invading Russian forces, has spoken frequently to leaders and supporters around the world, but only by phone and video conference.
But his trip acknowledges that the United States has been the most important supporter of the war effort, already providing some $20bn in security assistance and more in financial and humanitarian support.
Mr Zelensky made a surprise visit to soldiers in the key city of Bakhmut on the frontline in the Donetsk region of Ukraine earlier today.
The Ukrainian president congratulated military officials and gave awards to soldiers, who he thanked for their "courage, resilience and strength".