Ukraine leader Volodymyr Zelensky on Sunday rejected the idea of Russia offering his country security guarantees, after US and EU officials promoted the possibility.

White House envoy Steve Witkoff earlier said US President Donald Trump and his Russian counterpart Vladimir Putin agreed to "robust security guarantees" for Ukraine during a meeting in Alaska on Friday.

EU chief Ursula von der Leyen on Sunday hailed the proposal as an offer of NATO-style security guarantees from the United States.

"We welcome President Trump's willingness to contribute to (NATO) Article 5-like security guarantees for Ukraine, and the coalition of the willing, including the European Union, is ready to do its share," von der Leyen said.

Zelensky also welcomed the idea of US security guarantees -- but was less positive about Russia's intentions.

"What President Trump said about security guarantees is much more important to me than Putin's thoughts, because Putin will not give any security guarantees," he told a press conference in Brussels alongside von der Leyen.

"Security means a strong army, which only Ukraine can provide. I believe that only Europe can finance this army."

Von der Leyen and Zelensky also shared their thoughts on a possible meeting between Trump, Putin and the Ukrainian leader.

"So far, Russia gives no sign that the trilateral will happen and if Russia refuses, then new sanctions must follow," Zelensky said.

Von der Leyen had said she wanted to see the three-way meeting happen "as soon as possible".

Zelensky will meet Trump in Washington on Monday, accompanied by von der Leyen and other European leaders. (AFP)