U.S. diplomatic chief Marco Rubio today vigorously defended President Donald Trump’s cognitive abilities during a parliamentary hearing, dismissing concerns to that effect.

“I’ll tell you simply: you probably don’t appreciate his policies, you probably don’t appreciate the decisions that he’s made, but I assure you that he is not a president who is asleep or who is suffering from any cognitive disorder in any form,” Rubio told the House Foreign Affairs Committee.

The US secretary of state was responding to a question posed by Democratic Congressman Ted Liu, who presented videos showing President Trump falling asleep during meetings, questioning his cognitive abilities.

“Instead of holding North Korea-style cabinet meetings where everyone coddles Trump, I would ask you to tell it like it is: there is something wrong with Trump,” the congressman said.

“I don’t even know how to respond to that, other than to tell you that it’s absurd and ridiculous and I can’t believe we’re in a meeting of the House Foreign Affairs Committee at this critical time for American foreign policy,” responded the secretary of state, who is also the president’s national security adviser. The congressman said: “keep lying.”

According to Rubio, Donald Trump “literally does not sleep, he works around the clock, for long hours, every day (…) at an inhuman pace.”

The state of health of the US president, who will turn 80 on June 14, does not raise as many questions in the public mind as that of Joe Biden at the end of his term, when the Democrat frequently fell down and was in disarray.

But many Americans are raising doubts about his abilities. In a recent Washington Post/ABC News/Ipsos poll, 59 per cent of respondents felt Donald Trump lacked the mental capacity to run the country and 55 per cent said he lacked the necessary physical fitness.

The Republican leader’s latest in a series of medical reports, released last Friday, said he “remains in excellent health.”

Donald Trump is the oldest president ever sworn in.

The president has reduced the pace of his travel to the US compared to his first term and has appeared less frequently in public in recent months compared to the start of his second term.

However, he continues at the same pace of foreign travel and responds to the press much more frequently than his predecessor.

During that tense hearing, Rubio provoked the ire of Democratic elected officials who denounced the war in Iran and exclaimed “what a circus” when Democratic Rep. Sarah Jacobs asked him what he thought of a pair of shoes that were in a much larger size and offered to him by the U.S. president.