Kamala Harris 'ready to serve' as US president amid Biden's age scrutiny

US Vice President Kamala Harris has said she was ready to serve as leader, as voter concerns mount about President Joe Biden's age in an election year.

"I am ready to serve. There's no question about that," Harris said in a Wall Street Journal interview published on Monday, when asked whether voters' concerns about Biden's age meant she must convince them of her credentials.

The 59-year-old Harris has faced growing scrutiny about her own abilities as the first in line to the presidency should Democrat Biden, 81, be incapacitated or stand down.

Everyone who sees her on the job "walks away fully aware of my capacity to lead," said Harris, the first Black, South Asian and female vice president in US history.

The interview was carried out two days before a stinging special counsel report portrayed Biden as elderly and forgetful.

'Elderly man with a poor memory'

Special counsel Robert Hur's probe into Biden's handling of classified documents said the president should not face charges but damningly said he would come across to a jury as a "well-meaning, elderly man with a poor memory."

The White House has hit back hard at the report, noting that Hur interviewed Biden when he was under intense pressure the day after the October 7 attacks on Israel.

Harris also sprang to Biden's defense, branding the special counsel's report as "politically motivated."

Harris has taken on a growing role in Biden's reelection campaign, focusing on subjects including abortion, ahead of November's vote in which he is expected to face a rematch with former president Donald Trump.

Republicans have frequently targeted Harris and polls show the former California senator suffers from low approval ratings, like Biden himself.