WATCH: Joe Biden falls asleep during Climate Change Conference

GLASGOW: A video footage showing US President Joe Biden appears to fall asleep during opening sessions at the Cop26 climate conference in Glasgow, Scotland has gone viral on social media.

A video clip first shared by a reporter for The Washington Post shows Mr Biden listening to a speaker remarking that the world leaders assembled for the conference have the “power to make decisions and reach agreements which will affect the lives of generations to come” when the president appeared to close his eyes for roughly 20 seconds.

An aide then approached and began to whisper to Mr Biden, who turned his head to listen briefly before he began listening to the speech once more.

At 78, Mr Biden is the oldest person to serve as president of the United States, and his health and mental fitness for the job have been a subject of speculation by critics, including former president Donald Trump and his supporters.