US President Donald Trump's refusal to concede the election is diminishing democracy, former president Barack Obama said on Sunday.
He said it was clear Joe Biden would be the country's next leader and that Mr Trump's delay in accepting that would have repercussions.
"The president doesn't like to lose and never admits loss," Mr Obama told CBS's Sunday Morning programme.
Mr Obama criticised the Republicans who allowed Mr Trump to continue to make false claims about widespread voter fraud.
“It is one more step in delegitimising not just the incoming Biden administration, but democracy generally," he said.
Mr Obama said Mr Trump should remember that he is a public servant and a temporary occupant of the White House.
“And when your time is up then it is your job to put the country first and think beyond your own ego, and your own interests, and your own disappointments," he said.
“My advice to President Trump is, if you want at this late stage in the game to be remembered as somebody who put country first, it’s time for you to do the same thing.”
Mr Obama expressed concerns that if Mr Trump and his party continued down this path, America's adversaries would see it as a weakened country and try to exploit the "cleavages in the body politic".
In comments made last Friday regarding a coronavirus vaccine, Mr Trump said his administration would "not be going to a lockdown" to slow the spread of Covid-19.
“Whatever happens in the future, who knows which administration it will be? I guess time will tell," he said.
In a tweet on Sunday, Mr Trump appeared to accept Mr Biden's election victory, but recanted within 90 minutes.
Mr Trump followed that with a tweet about more lawsuits coming from his campaign to challenge the election result.
Mr Obama said that deepening divisions in the US were driven in part by the different mindset of Mr Trump’s supporters and the conservative media that feeds those views.
Mr Trump lost the popular vote to Mr Biden even though more than 73 million Americans cast their ballots for him.
“The power of the alternative worldview that’s presented in the media those voters consume – it carries a lot of weight,” Mr Obama said.
The former president did not cite a specific outlet, but he and Democrats have often criticised Fox News, which features a weeknight line-up of conservative hosts including Tucker Carlson and Sean Hannity, who have been ardent promoters of Mr Trump and his policies.
Mr Trump turned on the cable news channel recently, blasting its election coverage for being insufficiently loyal and suggesting in a tweet on Thursday that his supporters switch to more conservative choices.
“They forgot the Golden Goose,” Mr Trump said. “The biggest difference between the 2016 Election and 2020 was Fox News!”