The power transfer took place while Biden was under anaesthesia for a routine colonoscopy for one hour and 25 minutes, reported CNN.
The US’ first female, first Black and first South Asian vice president Harris broke another barrier as she became the first woman to hold presidential powers in the country.
Harris worked from her office in the West Wing while Biden was under anaesthesia, according to Psaki.
Biden spoke to Harris and the White House Chief of Staff on Friday morning.
“POTUS was in good spirits and at that time resumed his duties. He will remain at Walter Reed as he completes the rest of his routine physical,” Psaki tweeted.
Biden, who turns 79 on Saturday, arrived Friday morning at Walter Reed Medical Center to undergo his first routine annual physical since taking office, according to CNN
In the US, it is usual for a vice president to assume presidential powers whenever the president requires anaesthesia.
(With Inputs from ANI)