WASHINGTON (BLOOMBERG) - President Donald Trump again questioned the competence of Mr Joe Biden as the Democratic nominee continues to lead in polls ahead of the November election.

"Let Biden sit through an interview like this, he'll be on the ground crying for mommy," Mr Trump said in an interview on Fox News Sunday.

"He'll say, 'Mommy, mommy, please take me home.'"

Mr Trump added: "He can't do an interview. He's incompetent."

As the number of coronavirus cases surges in the US and Mr Biden gains in polls nationally and in battleground states, Mr Trump has tried to portray Mr Biden as unfit to assume office.

His campaign has repeatedly highlighted Mr Biden's gaffes and misstatements.

Asked whether he thinks Mr Biden is senile, Mr Trump responded: "I don't want to say that."

He added: "To be president, you have to be sharp and tough and so many other things. He doesn't even come out of his basement."

The Biden campaign did not immediately respond to a request for comment.

Mr Biden has made his campaign events almost entirely virtual, making about one public appearance a week before small groups of reporters and supporters and maintains strict social distancing and mask requirements for attendance.

He has been sharply critical of Mr Trump's handling of the coronavirus and is pushing a plan to revive the economy from the virus-related recession, offering a contrast with Mr Trump's insistence the economy is bouncing back.