US President Joe Biden joked about his future election opponent, Republican Donald Trump. The leader pointed out the age of his opponent, informs Reuters. Biden made the corresponding statement at the annual dinner of the Gridiron club. This is an annual event held in Washington since the 1880s. Each American president during their tenure is expected to participate in the event. Overall, Biden’s speech lasted about 10 minutes. The dinner was attended by over 650 guests, including Irish President Leo Varadkar, Amazon founder and Washington Post owner Jeff Bezos, and TikTok CEO Shou Zi Chew. “On…