Ukrainian President Volodymyr Zelenskyy unexpectedly canceled a scheduled videolink appeal to US senators Tuesday as Washington is set for a showdown on funding for the war with Russia.
Zelenskyy was to appear during a classified briefing, a day before the Senate takes the first procedural vote on an emergency aid package that includes more than $60 billion for Kyiv.
The cash has been held up for weeks by a row in Congress, as the White House has warned that existing funds will run out by the end of the year and that Russia's President Vladimir Putin could win the war if lawmakers fail to act.
"Zelensky by the way could not make it -- something happened at the last minute -- to our briefing," Senate Majority Leader Chuck Schumer said.
Underlining their urgent need to keep funds and arms flowing, top Ukrainian officials were making the rounds in the US capital in person.
Congress is more divided over backing for Ukraine than it has been at any time during the nearly two-year conflict, with the country fast exhausting the military aid provided by the United States so far.
Senate Republicans are conditioning their support for the funding on President Joe Biden's Democrats accepting measures to address migrant issues at the southern border -- reforms the Democrats have already rejected.
- Ukraine aid threatened -
"We can't ever put a price on defending democracy in its hour of need, because if Ukraine falls, Putin will keep on going," Schumer said before Zelenskyy's cancellation.
"Autocrats around the world will be emboldened. Democracy, this grand and noble experiment, will enter an era of decline."
Schumer has teed up a vote Wednesday on clearing the first procedural hurdle for addressing Biden's $106 billion aid request for Ukraine, Israel and Taiwan.
But it needs 60 votes in the 100-member Senate, and the 49-strong Republican minority looks likely to defeat the package as it leaves out their immigration reforms.
Texas Republican John Cornyn said in a speech on the Senate floor the proposal had "zero chance of becoming law."
"Our security cannot come second to that of other countries around the world, our allies, even those like Ukraine and Israel," he said.
Even if the two sides manage to hammer out a deal in the Senate, it will be a much tougher sell for the Republican-led House, where conservatives have been more skeptical about funding Ukraine, and just as keen to leverage the issue to secure border reforms.
House Speaker Mike Johnson confirmed publicly for the first time in a letter to the White House Tuesday that his party will not pass Ukraine aid unless Congress enacts "transformative change to our nation's border security laws."
Andriy Yermak, a top aide to Zelenskyy, thanked Americans for their support so far in an appearance in Washington hours before the president's scheduled address -- but added that more aid was needed to secure victory.
"It's very difficult for our people but Ukrainians are still very motivated," Yermak said at the U.S. Institute of Peace. "Our people believe and are sure that we will win."