On Monday, billionaire Elon Musk asked Twitter users to weigh in on a plan to end Russia's conflict in Ukraine that drew immediate condemnation from Ukrainians, including President Volodymyr Zelensky, who responded with his own poll.

"Which @elonmusk do you like more?," Zelensky tweeted, offering two responses: one who supports Ukraine, one who supports Russia.

Musk, the world's richest person, proposed UN-supervised elections in the four occupied regions that Moscow moved to annex last week after referendums. The votes were denounced by Kyiv and Western governments as illegal and coercive.

"Russia leaves if that is will of the people," Musk wrote.

The Tesla Inc chief executive suggested that Crimea, which Moscow seized in 2014, be formally recognised as Russia, that water supply to Crimea be assured and that Ukraine remain neutral. He asked Twitter users to vote 'yes' or 'no' on the plan.

"Dear @elonmusk, when someone tries to steal the wheels of your Tesla, it doesn't make them legal owner of the car or of the wheels. Even though they claim both voted in favour of it. Just saying," Lithuania's President Gitanas Nausėda tweeted in response.

Musk, who is also chief executive of SpaceX, followed up his first tweet with another poll: "Let's try this then: the will of the people who live in the Donbas & Crimea should decide whether they're part of Russia or Ukraine."

He said he didn't care if his proposal was unpopular, arguing that he did care "that millions of people may die needlessly for an essentially identical outcome".

"Russia has 3 times the population of Ukraine, so victory for Ukraine is unlikely in total war. If you care about the people of Ukraine, seek peace," he posted on Twitter.

In February, when Ukraine's internet was disrupted as the conflict began, Musk responded to a tweet by a Ukrainian government official seeking help. Musk said SpaceX's Starlink satellite broadband service was available in Ukraine and that SpaceX was sending more terminals to the country.

"SpaceX’s out of pocket cost to enable & support Starlink in Ukraine is ~$80M so far. Our support for Russia is $0. Obviously, we are pro Ukraine," Musk posted on Twitter later on Monday.