As of Monday morning, the country's overall caseload has increased to 1,752,347, while the death toll stood at 149,614, currently the fourth largest in the world.
Biden also noted the importance of cooperation, including through multilateral organisations, on shared challenges such as combatting climate change, containing COVID-19.
It is unclear exactly how the headdress, made of hundreds of long quetzal feathers and more than 1,000 gold plaques, ended up in Austria, where it is on display at a museum in Vienna.