President Donald Trump, who has largely vanished from public view since his election defeat, was to emerge Friday for a White House meeting on the Covid-19 vaccine drive.

For 10 days the Republican has been consumed by his pursuit of a conspiracy theory that Democrat Joe Biden won through massive ballot rigging.

Despite his own intelligence officials' declaration Thursday that the November 3 election was "the most secure in American history," Trump and his right-wing media allies show no sign of giving up their crusade.

"Biden did not win, he lost by a lot!" Trump asserted falsely again late Thursday while tweeting commentary on the Fox News evening show starring his booster Sean Hannity.

Trump has been tweeting day and often night on the unproven fraud claims.

But he has been absent from his normal presidential duties and notably silent about dramatically soaring coronavirus infection rates around the country and steadily rising deaths.

Friday's midday (1700 GMT) work session was marked as an "update" on Operation Warp Speed, the government partnership with pharmaceutical companies to create and distribute a vaccine.

The closed meeting marked a rare change in the president's public daily schedule which has mostly been empty since the election.

He has gone more than a week now without speaking in public or taking questions from journalists.

Split reality 

Trump and his senior aides are living increasingly in a split reality.

Despite a healthy majority of ballots tallied for Biden and days of failed attempts by Trump lawyers to present proof of significant irregularities, White House trade advisor Peter Navarro told Fox Business on Friday that his side remained convinced of victory.

"We think he won that election," he said. "We are moving forward here at the White House under the assumption that there will be a second Trump term."

Biden, meanwhile, is steadily preparing to take over on January 20 and the list of world leaders accepting that he will be the new president keeps lengthening.

China was the latest nation on board, with a foreign ministry spokesman saying "we express our congratulations."

However, Biden's newly appointed chief of staff, Ron Klain, told MSNBC late Thursday that moves by Trump to block the incoming administration from access to confidential government briefings posed a growing risk.

Klain highlighted the inability to join in on preparations for rolling out the Covid vaccine in "February and March when Joe Biden will be president."

"The sooner we can get our transition experts into meetings with the folks who are planning the vaccination campaign the more seamless," he said.

Top Republicans remain outwardly loyal to Trump, but there appears to be widening discomfort within the party over the blocking of Biden's transition team.

Senator James Lankford told Tulsa Radio KRMG earlier this week that he was giving Trump until Friday to allow Biden access to the daily presidential intelligence briefing or "I will step in."

John Bolton, a former national security advisor under Trump and a popular figure on the hawkish foreign policy wing of the Republican Party, said his side has to "acknowledge the reality that Biden is the president-elect."

"They may not like it but the country deserves to give him the preparation he needs," he told NPR radio Friday.

Since the election, Trump has only left the White House to play golf twice and to attend a brief Memorial Day ceremony at Arlington National Cemetery.