Biden won the Republican stronghold of Georgia, a top state official said after a manual recount, becoming the first Democrat to have won the key battleground state since 1992.
The embattled Trump campaign has stepped up efforts to challenge the results of the 2020 presidential election, making unverified claims that there was massive voters' fraud and electoral malpractice.
President Donald Trump's personal attorney Rudy Giuliani and a team of attorneys told reporters on Thursday that they are challenging vote count in Pennsylvania, Michigan and Georgia, among other states.
Former vice president Joe Biden was declared the winner of the presidential election on November 7 after flipping Pennsylvania, Michigan and Wisconsin to the Democrats' column.
Biden on Thursday won the Republican stronghold of Georgia, a top state official said after a manual recount, becoming the first Democrat to have won the key battleground state since 1992.
With Georgia's 16 electoral votes, Biden will now have 306 electoral votes to Trump's 232.
To win the race to the White House, the successful candidate should have at least 270 electoral votes out of the 538-member Electoral College.
President Trump has refused to concede the November 3 US election and has filed multiple lawsuits challenging poll results in several states.
"What I'm describing to you is a massive fraud," former New York mayor Giuliani told reporters at a Capitol Hill news conference as he and other attorneys gave an outline of their legal case that they are going to pursue over the next few weeks.
"This was not an individual idea of 10 or 12 Democrat bosses. This was a plan. You would have to be a fool not to realise that," the former mayor of New York City said, making unsubstantiated conspiracy theories and accusations of electoral fraud.
He said the media had shown an 'irrational pathological hatred for the President'.
Giuliani and his team alleged voter fraud in Atlanta, Detroit, Milwaukee, Philadelphia and several other cities that are controlled by the Democrats.
"We cannot allow these crooks -- 'cause that's what they are -- to steal an election from the American people. They elected Donald Trump; they didn't elect Joe Biden. Joe Biden is in the lead because of the fraudulent ballots, the illegal ballots that were produced and that were allowed to be used after the election was over. Give us an opportunity to prove it in court and we will," he alleged.
Legal advisor to the Trump campaign, Jenna Ellis, told reporters that they were laying out an 'introductory statement' with more to come.
"This is an elite strike force team that is working on behalf of the president and the campaign," she said.
"We are going to clean this mess up now. President Trump won by a landslide. We are going to prove it. And we are going to reclaim the
"United States of America for the people who vote for freedom," said Sidney Powell, a Trump campaign lawyer.
She alleged that the software used by election technology company Dominion Voting Systems 'can set and run an algorithm that probably ran all over the country to take a certain percentage of votes from President Trump and flip them to President Biden'.
She alleged that the voting machines from the Dominion were created 'at the direction' of former Venezuelan President Hugo Chavez to swing his own election results, and that the company has ties to the Clinton Foundation and Soros.
In a statement, Dominion rejected the accusations, and called 'a flood of absurdities'.
'Dominion is plainly a non-partisan American company with no ties to Venezuela or Cuba,' the company said.
'Dominion did not switch votes, rig elections, or engage in any election fraud. Dominion doesn't even operate in some of the contested districts, including Philadelphia, Milwaukee, and Dane, Wisconsin,' the company said on Thursday night.
Earlier in the day, Trump tweeted that the press conference would show 'a very clear and viable path to victory. Pieces are very nicely falling into place'.
Giuliani and his team of attorneys said that they had multiple pathways to victory.
The Trump campaign, however, voluntarily dismissed its lawsuit in Michigan.
It asserted that it had achieved its goal after two Republican members of the canvassing board in the county that includes Detroit tried to rescind their votes in favour of certifying the county's election.
Chris Krebs, the former director of the Cybersecurity and Infrastructure Security Agency, who was fired by Trump early this week slammed the press conference held by the Trump campaign.
'That press conference was the most dangerous 1hr 45 minutes of television in American history. And possibly the craziest. If you don't know what I'm talking about, you're lucky,' he tweeted.
The Washington Post alleged that Trump is using the power of Presidency to try to overturn the election and stay in office.
'After courts rejected the Trump campaign's baseless allegations of widespread voter fraud, the president is now trying to remain in power with a wholesale assault on the integrity of the vote by spreading misinformation and trying to persuade loyal Republicans to manipulate the electoral system on his behalf,' the daily wrote.
Meanwhile, after a hand recount of nearly five million votes, that lasted for several days, Democrat Biden won by 12,284 votes in Georgia over President Donald Trump. Before the recount Biden's lead was about 14,000 votes.
"Georgia's historic first statewide audit reaffirmed that the state's new secure paper ballot voting system accurately counted and reported results," said Georgia Secretary of State Brad Raffensperger on Thursday.
Georgia hadn't voted for a Democratic presidential candidate since Bill Clinton in 1992.
Officials said that the audit confirmed that there was no widespread fraud or irregularities in the election held on November 3.
"This is a credit to the hard work of our county and local elections officials who moved quickly to undertake and complete such a momentous task in a short period of time," the Republican official said.
The election results in Georgia, which has 16 electoral college votes, is expected to be certified on Friday.
Biden was declared the winner of the presidential election on November 7 after flipping Pennsylvania, Michigan and Wisconsin to the Democrats' column.
With Georgia's 16 electoral votes, Biden will now have 306 electoral votes to Trump's 232.
Trump won Georgia by 5 percentage points in 2016 over Democrat Hillary Clinton.