US President Donald Trump and his Russian counterpart Vladimir Putin agreed to "robust security guarantees" for Ukraine during their high-stakes summit in Alaska, a top White House envoy said Sunday.

"We agreed to a NATO-like robust security guarantees that I would describe as game-changing," Steve Witkoff said on CNN.

It was the “first time we had ever heard the Russians agree” to such a provision being included in a peace deal, he told CNN’s Jack Tapper on “State of the Union.”

EU chief Ursula von der Leyen on Sunday hailed US President Donald Trump's proposal to offer NATO-style security guarantees to Ukraine, as she hosted Ukraine leader Volodymyr Zelensky ahead of a key meeting in the White House the next day.

"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.

NATO-like guarantee

Witkoff said the clause — akin to NATO’s “Article 5” agreement that an attack against one is an attack against all — was a way of getting around Russia’s insistence Ukraine never be able to join NATO itself.

“Putin has said that a red flag is NATO admission. And so what we were discussing was assuming that that held, assuming that the Ukrainians could agree to that and could live with that — and everything is going to be about what the Ukrainians can live with — but assuming they could, we were able to win the following concession that the United States could offer Article 5-like protection,” he said.