Kamala Harris criticized her US election rival Donald Trump's "surrender" policy on Ukraine on Thursday, while the Republican said he would meet Ukraine's president despite a bitter row over the war with Russia.
Volodymyr Zelensky presented a so-called "victory" plan to President Joe Biden and Vice President Harris at the White House, with Biden announcing a new military aid package worth nearly $8 billion for a struggling Kyiv.
Standing with Zelensky at her side, Harris did not mention Trump by name but said there were "some in my country who would instead force Ukraine to give up large parts of its sovereign territory."
"These proposals are the same of those of (President Vladimir) Putin. And let us be clear, they are not proposals for peace. Instead, they are proposals for surrender," she said, referring to the Russian leader.
During a separate meeting in the Oval Office with Zelensky, Biden pledged that "Russia will not prevail" in the war it launched in February 2022.
"Ukraine will prevail, and we'll continue to stand by you every step of the way," Biden said.
Dressed in his trademark military-style outfit, Zelensky replied that "we deeply appreciate that Ukraine and America have stood side by side."
But Zelensky is navigating the choppy waters of a US presidential election on November 5 that could sink the staunch support that he has received from Washington in the past two-and-a-half years.
- 'Make a deal' -
Trump, who has long been critical of the billions of dollars in US support for Ukraine, accused Zelensky on the eve of the visit of refusing to strike a deal with Moscow.
But after the row had appeared to derail any meeting, Trump announced that he would hold talks with Zelensky at Trump Tower in New York on Friday.
"President Zelensky has asked to meet with me, and I will be meeting with him tomorrow morning at around 9:45," the Republican told reporters in New York.
Trump also repeated his longstanding claim that he would swiftly cut a peace deal -- which Kyiv fears would involve giving up land Moscow has already captured.
"I believe I will be able to make a deal between President Putin and President Zelensky and quite quickly," he said.
He also suggested he was displeased with Zelensky's recent comments to The New Yorker magazine in which Ukraine's leader said he believed Trump "doesn't really know how to stop the war."
Republicans have also been livid after Zelensky visited an arms factory in Biden's hometown in the battleground state of Pennsylvania, accusing the Ukrainian ambassador of organizing a partisan political event and calling for her to be sacked.
- 'They beat Napoleon' -
Trump has echoed many of Putin's talking points, saying at a rally earlier this week that Ukraine could not win as Russia "beat Hitler, they beat Napoleon, that's what they do."
When Trump was president he also asked Zelensky for potentially damaging political material on Biden ahead of the 2020 election -- which led to the first of the Republican's two impeachments.
Biden seems to be doing whatever he can to Trump-proof support for Ukraine as it faces an increasingly difficult situation on the battlefield against Russia.
He pledged nearly $8 billion in military aid on Thursday to "win this war," including $5.5 billion to be authorized before it expires at the end of the US fiscal year on Monday.
Biden, whose term ends in January, also called a summit of allies in Germany in October.
The White House, however, played down Zelensky's hopes of getting permission to fire long-range Western-made missiles into Russian territory.
"I'm not expecting there to be any new announcements," Press Secretary Karine Jean-Pierre said.
Zelensky earlier visited the US Congress and gave a defiant address at the UN General Assembly on Wednesday.
Zelensky's visit has prompted fresh nuclear saber-rattling from Moscow.
Putin on Wednesday announced plans to broaden Moscow's rules on the use of its atomic weaponry in the event of a "massive" air attack.