Ukrainian President Volodymyr Zelensky arrived in the US state of Pennsylvania on Sunday, kicking off a crucial visit in which he will present Kyiv's vision on how to end the war with Russia.

Zelensky is due to explain Ukraine's plan to President Joe Biden, as well as to Vice President Kamala Harris and, separately, to Republican presidential candidate Donald Trump.

"We have arrived in the United States of America," Zelensky said on social media.

"The plan for Ukraine's victory will be on the table for all our allies."

He said he was starting the trip in Pennsylvania for a "special visit" – without giving details – before travelling to New York and to Washington.

"Ukraine will present the victory plan in the United States, and the President of the United States will be the first to see it in full," Zelensky said in a video from a plane on route to Pennsylvania.

He will then present it to "all leaders of our partner countries" – as well as to the US Congress and "both presidential candidates," he added.

"It is this fall that will decide what will happen next in this war," said Zelensky.

"It is now being determined what the legacy of the current generation of states leaders will be. Those in the highest offices."

Zelensky is expected to try to convince Biden to allow Kyiv to strike targets inside Russia with delivered long-range western weapons, which he says would change the course of the war. (AFP)