Ukrainian President Volodymyr Zelenskyy will address US senators in a closed briefing on Tuesday, majority leader Chuck Schumer has said.
The meeting is scheduled for 3 pm EST and US national security officials will be involved.
The US is running out of time to help Ukraine win its fight against Russia, the White House has warned.
In October, Joe Biden's administration asked Congress for almost $106bn (£84bn) to fund plans for Ukraine, Israel and US border security.
Republicans who control the House with a slim majority rejected the package, however.
White House budget director Shalanda Young, in a letter to Mike Johnson, Republican speaker of the House of Representatives, and other congressional leaders, said cutting funding and a flow of weapons would "kneecap Ukraine on the battlefield" and increase the likelihood of Russian victories.
Ms Young added: "I want to be clear: without congressional action, by the end of the year we will run out of resources to procure more weapons and equipment for Ukraine and to provide equipment from US military stocks.
"There is no magical pot of funding available to meet this moment.
"We are out of money - and nearly out of time."
