The United States plans to announce more than $8 billion worth of military assistance for Ukraine on Thursday during Ukrainian President Volodymyr Zelenskiy's visit to Washington, two U.S. officials said on Wednesday.

President Joe Biden's administration has been engaged in urgent discussions with Congress to allow it to use up $5.6 billion in military aid for Ukraine before Sept. 30 - the end of the federal fiscal year - when the authority was set to expire.

On Thursday, U.S. officials said, the White House intends to notify Congress it will move forward with the announcement of a $5.6 billion drawdown from U.S. weapons stocks. The contents of that package are still in flux, the officials said.

Reuters reported this month that the Biden administration was considering a backup plan under which it would announce plans for shipments for Ukraine, but with an extended delivery timeline for the weapons and equipment, allowing for a more gradual transfer of resources to Ukraine without missing the Sept. 30 deadline.