Twitter users are accusing President Joe Biden of being asleep during opening sessions at the COP26 climate conference in Glasgow, Scotland.

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

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

       Mr Biden,78, 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.

       During his unsuccessful campaign for re-election in 2020, Mr Trump frequently accused Mr Biden of being senile, citing his occasionally-halting speech which is the product of a long-documented problem with stuttering.

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       The Independent has contacted the White House for comment.