Joe Biden and Kamala Harris celebrate outside the Chase Center after Biden accepted the 2020 Democratic presidential nomination in Wilmington, Delaware, U.S., August 20, 2020. REUTERS

Democrat Joe Biden was elected U.S. President on Saturday, with the counting of votes in a handful of battleground states ongoing thanks to a flood of mail-in ballots.

His projected victory came after four days of nail-biting suspense over the outcome of Tuesday’s election. The 74-year-old Biden promised to fight the coronavirus pandemic and fix the economy in a divided nation.

A Trump adviser acknowledged on Friday that the race had tilted against Trump, but said the president was not ready to admit defeat.

Mr. Biden has said his first priority will be developing a plan to contain and recover from the pandemic, promising to improve access to testing and, unlike Trump, to heed the advice of leading public health officials and scientists.

His victory was driven by strong support from groups including women, African Americans, white voters with college degrees and city-dwellers.

Mr. Biden, set to become the 46th U.S. president on January 20, mounted unsuccessful bids for the presidency in 1988 and 2008.

His running mate, U.S. Senator Kamala Harris, will become the first woman, the first Black American, and the first American of Asian descent to serve as vice president, the country’s No. 2 office.

Mr. Biden said he was “honored and humbled” to be elected.

“In the face of unprecedented obstacles, a record number of Americans voted. Proving once again, that democracy beats deep in the heart of America,” he said.