WASHINGTON, United States (AFP) — US President Donald Trump has yet to admit defeat in the US election. But with a word here, a slip there, he is raising the prospect ever more plainly.

In a tweet yesterday morning, Trump appeared accidentally to acknowledge Joe Biden’s victory before quickly reversing course to claim he won, and again push unsubstantiated claims of mass electoral fraud.

“He won because the Election was Rigged,” Trump tweeted.

The first two words — days after a verbal slip in which Trump said “time will tell” if he remains president — were immediately seized upon as one more step towards a concession.

But the president soon made a U-turn, tweeting: “He only won in the eyes of the FAKE NEWS MEDIA. I concede NOTHING!”

President-elect Joe Biden captured 306 electoral college votes in the November 3 election — 36 more than needed to win the White House, and the exact number Trump deemed a “landslide” when he won in 2016.

Senior federal and state election authorities, including a top cybersecurity agency, have rejected claims of widespread election fraud.

Still, Trump continues to insist he will prove fraud and prevail in court.

Meanwhile, the leaders of nearly every country in the world have congratulated Biden on his victory, reinforcing the notion that no one is taking the Trump legal challenges seriously.

Those challenges have been almost universally dismissed by judges as unfounded.

Reacting to Trump’s tweet, Biden’s newly named Chief of Staff Ron Klain told NBC‘s Meet the Press it was “further confirmation of the reality that Joe Biden won the election”.

“If the president’s prepared to begin to recognise that reality, that’s positive,” he said.

Some Administration officials say privately that they understand that Biden won, but that the president needs time to “process” his loss. Others, on the outside, speculate he may be trying to galvanise his base of support for a new run in 2024.

Until now, the president has refused to cooperate in the shift to a Biden Administration — denying the Democrat both federal funding for transition work and vital briefings by outgoing officials.

Democrats say this could have a damaging impact both on national security and on the grave and mounting challenges posed by the novel coronavirus pandemic.

Former President Barack Obama told CBS‘s Sunday Morning that it was clear that “Joe Biden will be the next president of the United States”, but added that Trump’s delay in acknowledging that comes at a price.

“There’s damage to this,” Obama said, adding that millions of people would believe there was fraud because the president said so.

Bernie Sanders, the progressive senator, who had sought the Democratic nomination, called Trump’s refusal to concede “absolutely disgraceful”.

“The idea that he continues to tell his supporters that the only reason he may have lost this election is because of fraud is an absolutely disgraceful, un-American thing to do,” he told CNN‘s State of the Union.

“I would just hope to God he has the decency in him to man-up and say, ‘You know what? We fought hard, we lost the election, good luck to Joe Biden.’ “

A small but growing number of Republican figures have begun pressing for Trump to concede defeat.

“It’s clear that, certainly based on what we know now, that Joe Biden is the president-elect,” Ohio’s Republican governor, Mike DeWine, said on CNN.

“For the country’s sake, it’s important for a normal transition to start,” he added.

And former Trump National Security Advisor John Bolton, a critic of the president since leaving the Administration, told CNN it was critical for other Republicans to make clear to Trump that he had lost in a fair election.

Bolton added: “I don’t expect him to go graciously. I do expect him to go.”

More than 10,000 Trump supporters rallied in Washington on Saturday to back his claims of fraud, massing in Washington’s Freedom Plaza before marching to the Supreme Court in a raucous atmosphere.

After dark, skirmishes erupted as Trump supporters and counter-protesters clashed on the streets, scuffling and throwing punches.

At least 20 people were arrested, reports said, including four for firearm violations and one for assault on a police officer.

Trump himself made a drive-past of the rally in his armoured motorcade, on his way to play golf, smiling through his limousine window to wild cheers.