U.S. Treasury Secretary Janet Yellen, asked Tuesday whether she had seen any evidence of mental decline in President Joe Biden, said the president was extremely effective in meetings in which she participated, including with foreign leaders.

"The president is extremely effective in the meetings that I've been in with him," Yellen told members of the House Financial Services Committee. "That includes many international meetings that are multi-hour, like his meetings with (Chinese) President Xi (Jinping)."

Yellen declined to say when she last met with him in person.

She said she was not aware of any discussions among cabinet secretaries on invoking the 25th Amendment to the U.S. Constitution, which enables the vice president and cabinet members to declare the president is unable to discharge the powers and duties of the office and transfer the job to the vice president. Republican Representative Mike Lawler from New York pressed Yellen on whether she had seen any mental or cognitive decline in Biden, 81, given concerns raised after his June 27 debate against Republican Donald Trump, where he appeared frail and at times lost his train of thought.

Representative Joyce Beatty, a Democrat from Ohio, interrupted Lawler's questions, moving to have Yellen's testimony struck from the record since she was not a physician, prompting Republican Blaine Luetkemeyer, who was chairing the hearing, to cut off further discussion on the issue. Biden is battling criticism from some Democrats that he lacks the mental acuity to stand as their nominee against Trump in the Nov. 5 presidential election. Biden insists that he will not abandon his campaign, calling the debate "a bad episode."

The White House on Monday said Biden is not being treated for Parkinson's disease and has not seen a neurologist outside of his annual physicals. It said his doctors had seen no reason to conduct a cognitive test.

Earlier, news had emerged that a specialist in Parkinson's had visited the White House eight times from August through March.