Speaking to a meeting of Russian ambassadors in Moscow on Friday, Mr Putin called on the Ukrainian government to withdraw from four regions partially occupied by Russia - Donetsk, Luhansk, Kherson and Zaporizhzhia.
He also said Ukraine would need to officially give up in its efforts to join the Nato military alliance for the Russian advance to be halted.
Mr Putin said: "As soon as Kyiv declares that it is ready for such a decision... an order to cease fire and begin negotiations will immediately follow from our side, literally at the same minute."
Ukrainian presidential adviser Mykhailo Podolyak called the proposal a "complete sham" and "offensive to common sense".
Later on Friday, President Zelensky told Italy's Sky TG24 television: "These messages are ultimatum messages. It's the same thing Hitler did, when he said 'give me a part of Czechoslovakia and it'll end here'."
@ISIDEWITH2 setmanes2W
Is comparing Putin's ultimatum to Hitler's demands historically accurate or an exaggeration, in your opinion?
