Russia said Saturday that Ukrainian President Volodymyr Zelensky's trip to the United States had been a "failure", after US President Donald Trump berated him in a stunning televised confrontation.

Zelensky planned to sign a minerals deal with the United States during the visit, but it ended in disaster when Trump and Vice President JD Vance accused the Ukrainian leader of being "disrespectful" and admonished him in front of US and international media.

Kyiv had hoped the agreement would pave the way for security guarantees from Washington, as it fights the full-scale offensive Russia launched in 2022.

"The visit of the head of the neo-Nazi regime, V. Zelensky, to Washington on February 28 is a complete political and diplomatic failure of the Kyiv regime," Russian foreign ministry spokeswoman Maria Zakharova said in a statement.

Moscow often accuses Ukraine of harbouring "neo-Nazism" and used that as a pretext to start its Ukraine offensive, an accusation that Western leaders and Kyiv call false and absurd.

"With his outrageously boorish behaviour during his stay in Washington, Zelensky confirmed that he is the most dangerous threat to the world community as an irresponsible warmonger," Zakharova said.

Accusing Zelensky of being "obsessed" with continuing the fighting, Zakharova added that Russia's military goals in Ukraine were "unchanging".

Moscow has been gaining ground on the battlefield for over a year, pressing their advantage against Ukraine's overstretched and outgunned army.