"Thank you first of all," Zelenskiy told the US president in a meeting in the Oval Office. "It's a great honour to be here."
The Ukrainian president, who said he had wanted to come to the United States earlier, on Wednesday offered his appreciation to Biden, the US Congress and ordinary Americans for their support.
He gave Biden the Ukrainian cross for military merit, offered by a captain it had been awarded to. Biden promised to give the captain a command coin from a US battlefield in Iraq, where his son Beau had fought.
"You are the man of the year," he told Zelenskiy of Time Magazine's decision to put him on the cover.
Biden said Russian President Vladimir Putin is "escalating his assaults on civilians" and trying to "use winter as a weapon".
Zelenskiy arrived at the White House's South Lawn in a black Chevrolet with tinted windows, wearing his trademark olive green sweater and cargo pants.
He stood between Biden and his wife Jill for a photo, then Biden put his arm around him as he guided him inside.
Zelenskiy said he would hold talks with Biden to strengthen Kyiv's defense capabilities against Russia's devastating invasion.
He will participate in a joint news conference with the U.S. president and then Zelenskiy will go to Congress on Capitol Hill to address a joint meeting of the US Senate and House of Representatives.