"All of them are from different sectors of the front ... Some of the boys were held captive for more than two years," he said on Telegram.
Russia and Ukraine on Wednesday exchanged 150 prisoners of war each after mediation by the United Arab Emirates, the Russian defence ministry said.
It said all of the freed Russians were currently in Belarus, where they were receiving psychological and medical assistance.
Prisoner exchanges have been running smoothly despite the lack of substantial talks on a peace solution to the war.
Ukraine had lost 45,100 soldiers on the battlefield since Russia's all-out invasion began nearly three years ago, Zelenskiy said in an interview with UK journalist Piers Morgan published on YouTube.
Zelenskiy put the number of injured soldiers at 390,000.
The figures cannot be independently confirmed.
While both Ukraine and Russia report enemy losses daily, they rarely disclose their own casualty numbers.
It is generally accepted that both sides play down their own losses and exaggerate those of the enemy.
US and European intelligence services estimate up to 100,000 Ukrainian soldiers and more than twice as many Russian soldiers have died in the conflict.
In addition, there are thousands of civilian casualties, mainly on the Ukrainian side.
Zelenskiy also said he is willing to enter into direct negotiations with Russian President Vladimir Putin during the interview with Morgan.
In addition to Ukraine and Russia, the United States and Europe should also be involved in the talks, Zelenskiy said.
It was unclear whether Zelenskiy was referring to the European Union or to individual member countries.
"If this is the only way to bring peace to the people of Ukraine and to avoid further loss of life, we will definitely go to this meeting with these four participants," he said.
"I will not be nice to him, I consider him an enemy, and frankly I think he considers me an enemy too," Zelensky said.
Kremlin spokesman Dmitry Peskov quickly dismissed Zelenskiy's comments as "empty talk," telling the Russian state news agency TASS that the Ukrainian president had banned himself from negotiating with Putin.
Peskov was referring to a decree signed by Zelenskiy in September 2022, after Russia annexed the four partially occupied Ukrainian provinces of Luhansk, Donetsk, Zaporizhzhia and Kherson.
While the decree does not prohibit negotiations with the Russian leader, it states that they are impossible in view of the situation.
Zelenskiy recently said the document was intended to prevent potential separatism because Russia was looking for unofficial communication channels with Ukraine at that time.
Russian authorities said on Wednesday that a Ukrainian drone attack had set a fuel depot on fire in the southern Krasnodar region.
Krasnodar Governor Veniamin Kondratyev wrote on Telegram that the drone attack had been repelled but that debris fell on a tank and sparked a fire.
Authorities said that the fire had been extinguished and there were no casualties.
The Ukrainian general staff later confirmed the attack.
with DPA
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