Washington (AFP) - Kamala Harris on Thursday criticized her US election rival Donald Trump’s stance on Ukraine, describing it as a policy of “surrender” to Russia as she told President Volodymyr Zelensky that he could rely on her support.

Zelensky also met President Joe Biden to present his “victory plan,” with the White House announcing a fresh military aid package worth nearly $8 billion for Kyiv as it struggles on the battlefield in the third year of Moscow’s invasion.

Zelensky’s visit has been clouded by a blazing row with Republican presidential candidate Trump that underscored how November’s US election could upend the support that Ukraine receives from its biggest backer.

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, who would demand that Ukraine accept neutrality.”

“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 with Zelensky by her side.

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 after thanking him for presenting the so-called victory plan.

Dressed in his trademark military-style outfit, Zelensky replied that “we deeply appreciate that Ukraine and America have stood side by side.”

- ‘Win this war’ -

Zelensky is looking to shore up support for his war effort as Biden tries to lock in aid for Ukraine, ahead of the white-knuckle US election on November 5.

Biden pledged nearly $8 billion in military aid on Thursday, including $5.5 billion to be authorized before it expires at the end of the US fiscal year on Monday.

Biden said in a statement that the “surge in security assistance for Ukraine” would “help Ukraine win this war.”

Biden also announced Washington would provide Ukraine with the Joint Standoff Weapon (JSOW) long-range munition and called a summit of allies in Germany in October.

The White House however played down Ukraine’s hopes that Zelensky’s visit would achieve his long-held goal of getting permission to fire long-range Western-made missiles into Russian territory.

“I’m not expecting there to be any new announcements on this particular action or a decision coming out of this meeting,” Press Secretary Karine Jean-Pierre told reporters.

Zelensky also visited the US Congress – where his government said he had also presented his victory plan – and gave a defiant address at the UN General Assembly on Wednesday.

But Zelensky’s visit has prompted fresh nuclear saber rattling from Moscow, which has repeatedly warned the West against giving Ukraine long-range arms.

- ‘Irresponsible’ nuclear threats -

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.

US Secretary of State Antony Blinken called the nuclear threat “totally irresponsible” while EU foreign policy spokesman Peter Stano said Putin was making a “gamble with his nuclear arsenal.”

Kyiv faces an increasingly difficult battlefield situation two and a half years into Russia’s invasion, with Russian forces continuing to push into eastern Ukraine.

The US presidential election means Washington’s now support now hangs on the balance.

Trump had also been due to meet Zelensky during his US visit, but their talks appear to be on ice.

Trump accused Zelensky on the eve of the visit of refusing to strike a deal with Moscow and once again questioned why the United States was giving billions of dollars to Kyiv.

At an election rally on Wednesday, the Republican called the Ukrainian president “probably the greatest salesman on Earth.”

Republicans were livid after Zelensky visited an arms factory in Biden’s hometown in the battleground state of Pennsylvania earlier this week, with House Speaker Mike Johnson calling for the Ukrainian ambassador to be sacked.

Trump has echoed many of Putin’s talking points about previous US policy being to blame for the Russian invasion, and has been critical of Zelensky for years.