President-elect Joe Biden said it was "time to turn the page" after US electoral college representatives on Monday submitted their votes to certify the results of the 2020 presidential election.
Mr Biden clinched the required 270 votes to become president-elect, beating the incumbent, President Donald Trump.
"The flame of democracy was lit in this nation a long time ago," Mr Biden said in a prime-time speech.
"And we now know that nothing, not even a pandemic, or an abuse of power, can extinguish that flame."
The electoral college vote between Mr Biden and Mr Trump ended 306-232 in favour of Mr Biden, with no faithless electors voting against the wishes of the people.
Mr Trump, meanwhile, continues to make claims of electoral fraud and still refuses to concede to Mr Biden.
"Three hundred and six electoral votes is the same number that Trump and Pence received when they won in 2016," Mr Biden said on Monday night.
"At the time, Trump called his electoral college tally a landslide. By his own standards, these numbers represented a clear victory then and I respectfully suggest they do so now."
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A lawsuit led by the Texas attorney general and supported by Mr Trump tried to overturn the election results in some swing states, including Georgia, Michigan, Pennsylvania and Wisconsin.
The lawsuit was rejected by the US Supreme Court on Friday.
All of those battleground states, and two others in which Mr Trump contested election results, voted in favour of Mr Biden on Monday.
By law, every US presidential election year, electoral college representatives meet in their state capitols to cast their votes on the second Monday of December.
The electors this year took extra precautions for reasons related to the pandemic, and for security because electors in Michigan received death threats. Nevertheless, the day developed without many surprises.
“The electoral college votes which occurred today reflect the fact that even in the face of a public health crisis unlike anything we’ve experienced in our lifetimes, the people voted," Mr Biden said.
The results from Monday's vote will be sent to Washington for the Congressional session on January 6.
The votes will be counted during the joint House and Senate session, paving the way for inauguration on January 20, when Mr Biden will be sworn in as the 46th US president.
Shortly after Mr Biden clinched the electoral college votes required to win, Mr Trump tweeted an announcement that Attorney General William Barr was resigning and would leave his position before the Christmas holiday.
Mr Barr disputed that there was any evidence of electoral fraud this year, contrary to Mr Trump's claims.