Harris was caught on camera Friday immediately wiping her right hand on her jacket after shaking hands with South Korean President Moon Jae-in at the White House.
Harris and Moon discussed North Korea, global health and the "root causes" of migration to the U.S. from Central America, Harris later wrote on Twitter.
Many social media users accused the vice president of being rude to Moon – with some claiming a Republican leader would have faced much harsher criticism for the same action.
"This is the USA VP?" one user wrote. "Not only disrespectful, but it would be ‘racist’ if this was a Republican, all over the news for sure….Double standards on full display."
"Wow! That’s so embarrassing!" another wrote.
"Is South Korea not our ally anymore," one Twitter user commented.
"You can’t wipe off a virus on your pants," another observed. "Plus, Kamala is fully vaccinated."
The vice president’s sense of decorum was previously called into question in late March, when sharp-eyed media watchers noticed the vice president hadn’t saluted U.S. military personnel as she climbed the steps to board Air Force Two.
Fox News found that Harris had also skipped salutes on several other prior occasions.
Weeks after the criticism, Harris posted a video on Twitter that showed her saluting before boarding a flight to North Carolina.
Fox News’ Evie Fordham contributed to this story.