Former Vice President Joe Biden should take the same cognitive test that President Donald Trump recently took, the latter said in an interview with Fox News.

“In a way he has an obligation to,” Trump said of the presumptive Democratic presidential nominee, adding that the presidency requires “stamina” and "mental health.”

According to him, he himself took a test to prove to the media that he is fit for the presidency after reports questioning his cognitive abilities. Trump believes 77-year-old Biden, who is three years older than Trump, is too old to run for president.

“Because I can tell you President Xi [Jinping of China] is sharp, [Russian] President [Vladimir] Putin is sharp, [Turkish President Recep] Erdogan is sharp. You don’t have any non-sharp people that you’re dealing with,” Trump noted.