WASHINGTON • Democratic presidential candidate Joe Biden and former president Barack Obama have blasted Republican President Donald Trump's handling of the coronavirus pandemic in a video, as the Biden campaign tapped the star power of America's first black president.

Mr Biden, who was vice-president in the Obama administration, sat down facing Mr Obama in a chair across a room for a "socially distanced" conversation.

They released the video on Thursday on Twitter, where Mr Obama has 120.8 million followers, the most on the platform.

"Can you imagine standing up when you were president, saying, 'It's not my responsibility?' " Mr Biden asked Mr Obama, referring to Mr Trump's efforts to evade criticism for his response to the coronavirus pandemic.

"Those words didn't come out of our mouths when we were in office," Mr Obama replied.

In response, Mr Trump attacked them on Twitter, writing: "Remember, I wouldn't even be here if it weren't for them. They did a terrible job!"

With traditional campaigning still in limbo due to the pandemic, the video offered a glimpse of how Mr Obama - still overwhelmingly popular among Democratic voters - may be deployed to build enthusiasm for November's presidential election.

During their first in-person meeting since Mr Biden became the presumptive Democratic nominee, the two men spoke about the need to expand on the Affordable Care Act (ACA), also known as Obamacare, their administration's signature programme that vastly expanded US healthcare coverage.

The Trump administration has petitioned the US Supreme Court to invalidate the ACA.

"It is hard to fathom anybody wanting to take away people's healthcare in the middle of a major public health crisis," Mr Obama said.

They also discussed Mr Biden's ability to empathise, a trait his campaign has stressed to contrast him with Mr Trump.

"I don't understand his inability to get a sense of what people are going through," Mr Biden said. "He can't relate in any way."

Mr Obama said: "It is a sign of leadership when you are willing to hear other people's experiences."

REUTERS