US first lady Jill Biden has said her husband’s age is an “asset”, as President Joe Biden – at 81 already the oldest American leader in history – faces persistent questions from voters about his decision to seek another term.

In an interview with MSNBC’s Morning Joe released on Thursday, Ms Biden responded to those concerned the Democratic president is too old, saying: “I say his age is an asset.”

“He has wisdom. He has experience,” she continued.

“He knows every leader on the world stage. He’s lived history. He knows history. He’s thoughtful in his decisions. He is the right man or the right person for the job at this moment in history.”

Mr Biden has for months used humour to try to defuse the issue – even as polls suggest it is no laughing matter.

An August poll from The Associated Press-NORC Centre for Public Affairs Research found that 77% of US adults, including 69% of Democrats, viewed Mr Biden as too old to be effective for four more years.

When Mr Biden celebrated his 81st birthday on November 20 2023, he joked repeatedly about his advanced age, saying it was “difficult turning 60” and promising he was not at a ceremony for pardoning Thanksgiving turkeys when the tradition started 76 years earlier: “I want you to know I wasn’t there – for the first one.”

But while Mr Biden was poking fun at his age, the White House was busy defending his stamina and trying to bat away suggestions the issue could cost him votes in this year’s election.

Press secretary Karine Jean-Pierre said then that the president’s age should not be a primary focus.

“Our perspective is it’s not about age, it’s about the president’s experience,” she said, highlighting several major pieces of legislation he had championed through Congress.