Last month, Time magazine cited an anonymous White House source as saying it's unlikely that President Joe Biden will attend King Charles' coronation at Westminster Abbey on May 6.

The Daily Telegraph appears to have confirmed the claim, reporting that Biden's advancing age and deteriorating condition will force him to officially withdraw from the event.

Biden already has two other overseas trips planned

The Telegraph noted how Biden is already scheduled to visit Northern Ireland in the coming days as well as attend the G7 summit in Japan next month.

That has reportedly led to concerns that another trip for the King's coronation could leave the president "too tired to perform his domestic duties."

"The guy is 80," an unnamed White House source was quoted by the Telegraph as saying. "They space out his big bursts of activity quite considerably."

The prospect of Biden avoiding the coronation doesn't go over well with Conservative Member of Parliament Bob Seely, who serves on the House of Commons' Foreign Affairs Select Committee.

Some consider Biden's withdrawal "foolish"

He told the Telegraph that such a decision would be "foolish," adding, "It seems pretty remiss, and I’m tempted to say more fool him for not coming."

"This is a once-in-a-lifetime event, and you would have thought he should come because he’s a head of state," Seely continued.

"If I was the President of the United States, I would come to the Coronation of the King of England – there’s no two ways about it," the British lawmaker insisted.

However, Conservative Member of Parliament Tobias Ellwood says he would not be troubled by the president's absence.

First lady may attend coronation in the president's place

"Whilst we’d hope Joe Biden would be invited, there is no historical protocol for a US president to attend royal coronations, so we should not read too much into any absence," Ellwood told the Telegraph. "America will be represented, and it will be telling who the president chooses to send."

The New York Post reported on Saturday that First Lady Jill Biden may travel to the United Kingdom in her husband's place.

Many have argued that Biden is not mentally competent to serve as president, and they include former White House physician Ronny Jackson.

"The majority of Americans can see that Biden's mental health is in total decline, yet there is no transparency from the White House on what’s going on, if anything, to address this issue and his inability to do his job," Jackson told Fox News in February.