Joe Biden yesterday reached the two-week mark since becoming president-elect, with President Donald Trump stinging from back-to-back setbacks in his desperate, unprecedented bid to undo his election defeat. 

Biden, a Democrat, is preparing to take office on Jan. 20, but Trump, a Republican, has refused to concede and is seeking to invalidate or overturn the results through lawsuits and recounts in a number of states, claiming - without proof - widespread voter fraud.

That effort, which critics call an unparalleled push by a sitting president to subvert the will of voters, has met with little success. Trump's campaign has suffered a string of legal defeats and appears to have failed to convince key fellow Republicans in states that he lost, such as Michigan, to buy into his unfounded conspiracy theories.

Trump's bid to cling to power appeared ever more tenuous on Friday after Georgia Secretary of State Brad Raffensperger announced a manual recount and audit of all ballots cast in the southern state had confirmed Biden as the winner there.

A pair of Michigan Republican leaders delivered another blow when they declared on Friday night after a White House meeting with Trump: "We have not yet been made aware of any information that would change the outcome of the election in Michigan."

Trump, in his first public comments in days about the election outcome, again asserted "I won" during a White House event on lowering drug prices earlier on Friday.

After a series of court defeats, the Trump team is resting its hopes on getting Republican-controlled legislatures in battleground states won by Biden to set aside the results and declare Trump the winner, according to three people familiar with the plan.

It is a long-shot effort focusing on Michigan and Pennsylvania for now, but even if both those states flipped to the president he would need to overturn the vote in another state to vault ahead of Biden in the Electoral College.

Such an event would be unprecedented in modern US history.

Biden, who became president-elect on Nov. 7 after his win in Pennsylvania prompted major television networks to call the election, was due to spend yesterday meeting with Vice President-elect Kamala Harris and transition advisers.

Trump will participate virtually this weekend in the last summit of the 20 biggest world economies (G20) of his term.

Pressure for Trump to start the formal transition process has mounted, with a few more Republicans voicing doubts over his unsubstantiated claims of fraudulent voting.

A Thursday press conference in which Trump lawyer Rudolph Giuliani posed a series of election conspiracies that he said were waged against Trump, without providing any evidence, may have been a turning point for some former allies, two Republican sources said. They noted a lack of logic in Giuliani's presentation that they said undercut the president's argument.

Senator Lamar Alexander, who is retiring at the end of the year, said Biden had a "very good chance" of becoming the next president, and urged the Trump administration to begin the transition process. The loser of this election should "put the country first, congratulate the winner and help him to a good beginning of the new term," the Tennessee senator wrote in a statement.

Michigan Representative Fred Upton told reporters Friday, "I've not seen any evidence of fraud that would overturn 150,000 and some votes" that Biden leads Trump by in his home state. "No one has shown any evidence" of fraud in Michigan, Upton said.

There is a "right way and a wrong way" for Trump to contest what he sees as election irregularities, Susan Collins, the Maine Senator, said in a statement. "The right way is to compile the evidence and mount legal challenges in our courts. The wrong way is to attempt to pressure state election officials."

Biden should receive the "briefings, office space, and access to government resources he needs to be ready to govern on Inauguration Day," Collins said.

Alaska's conservative Senator Dan Sullivan told reporters Trump has "a high bar" to prove his claims the election has been stolen by Democrats. "And they've got to prove it in court," Sullivan said.

The General Services Administration, run by a Trump appointee, still has not recognized Biden's victory, preventing his team from gaining access to government office space and funding normally provided to an incoming administration.

Critics say Trump's refusal to concede has serious implications for national security and the fight against the coronavirus, which has killed more than 250,000 Americans.

Official certifications of election results in the 50 states have started rolling in, and are expected to show that Biden won some 6 million votes more than Trump, and 306 votes in the Electoral College that determines the winner, compared to Trump's 232.