Ukraine President Volodymyr Zelensky arrived in Washington, D.C., on Sunday night, saying he was grateful for President Trump’s invitation and wanted to end the war with Russia “quickly and reliably.”

He also said that if there is a peace deal, it must be set up to be lasting to avoid a situation where Russia might invade Ukraine again.

He specifically noted Russia’s taking of Crimea and parts of the Donbas region, saying in a post on X that a new deal couldn’t be set up to give Russian President Vladimir Putin things that he could then use as a springboard for a new attack.

Zelensky also criticized “security guarantees” he said were given to Ukraine in 1994 that didn’t work.

“And peace must be lasting. Not like it was years ago, when Ukraine was forced to give up Crimea and part of our East—part of Donbas—and Putin simply used it as a springboard for a new attack. Or when Ukraine was given so called “security guarantees” in 1994, but they didn’t work.

“Of course, Crimea should not have been given up then, just as Ukrainians did not give up Kyiv, Odesa, or Kharkiv after 2022. Ukrainians are fighting for their land, for their independence,” he wrote.

“I am confident that we will defend Ukraine, effectively guarantee security, and that our people will always be grateful to President Trump, everyone in America, and every partner and ally for their support and invaluable assistance,” Zelensky said.

“Russia must end this war, which it itself started. And I hope that our joint strength with America, with our European friends, will force Russia into a real peace. Thank you!”

U.S. officials on Sunday said Ukraine may get security guarantees similar to NATO Article 5 guarantees in which European countries and the U.S. would commit to defending Ukraine, though not NATO itself.