Zelenskyy gives Biden a medal at White House as US pledges extra $1.85bn for Ukraine
Mr Zelenskyy handed his US counterpart the medal on behalf of a Ukrainian soldier.
Speaking at the White House, he explained that a man from Bakhmut had asked him to give his military medal to the US President.
"Undeserved but much appreciated," Mr Biden said in response.
He asked Mr Zelenskyy to take a challenge coin back to the soldier.
Speaking in English, Mr Zelenskyy said "it is a great honour" to be at the White House, thanking Mr Biden and the "ordinary people" of America for their support.
"Thanks from our ordinary people, to your ordinary people, Americans. I really appreciate you," he said
"I think it's really difficult to understand what we say when we say we appreciate... it's a great honour to be here."
It comes after the US announced that it would be providing a further $1.85 billion in military aid to Ukraine - including the first transfer of the Patriot air defence system.
The Patriot is an anti-missile missile used for taking down ballistic and cruise missiles.
Ukraine has been asking for the air defence system to help make a stand against Russian missile and drone attacks.
Most recently, Putin has been targeting the country's energy infrastructure, leaving millions of Ukrainians without power and water.