United States President Donald Trump meets Ukrainian leader Volodymyr Zelensky on Tuesday as patience wears thin on Russia, at a UN summit where the US president is expected to offer a dark take on the future of the world body.

Trump will address the United Nations for the first time since he returned to office and quickly took to slashing the US role in international organizations.

It will be Trump’s second time seeing Zelensky since the US leader invited Russian President Vladimir Putin on 15 August to Alaska, a meeting that broke Moscow’s isolation in the West but yielded no breakthrough on Ukraine.

Russia has not only kept up its barrage of attacks on Ukraine in the past month but has increasingly raised fears in the West, with drone or air incursions in North Atlantic Treaty Organization (NATO) members Poland, Estonia and Romania.

Mike Waltz, newly installed as the US ambassador to the United Nations, voiced solidarity over the airspace violations.

“The United States and our allies will defend every inch of NATO territory,” said Waltz, who was earlier Trump’s national security advisor.

Trump took office vowing that he could end within one day the Ukraine war, which has claimed tens of thousands of lives, and boasted of his personal chemistry with Putin.

But Trump acknowledged last week that Putin had “really let me down.”

Zelensky is expected to press Trump to take a harder line and impose long-threatened new sanctions on Russia.

But Secretary of State Marco Rubio, last week previewing the talks with Zelensky, said that Trump was not ready to pressure Putin, saying that without him, “there’s no one left in the world that could possibly mediate” on Ukraine.