Democrat Adam Schiff has accused US Attorney General William Barr of lying in connection with his claim that China poses a greater threat to the US presidential election than Russia.

This is just a plain, Adam Schiff told CNN adding that Barr's statement misled the American people.

"That's just a plain, false statement by the Attorney General. A flat-out false statement," Schiff said, maintaining, "you can tell that Bill Barr is just flat-out lying to the American people, and it's tragic but it's as simple as that."

Barr has already said that China poses a greater threat than Russia when it comes to alleged interference in the US elections.

When asked if Barr was lying, Schiff noted that basically, that's what he does and this is the reality.

Trump's electoral rival, former Vice President Joe Biden, said earlier that he disagrees that China is the biggest threat to the election and that such an assessment is inconsistent with intelligence reports he received.