Harris and Trump each need at least 270 electoral votes to win the presidency in an election that is seen as one of the most significant in recent US history.
Trump, who served as the 45th president of the United States from 2017 to 2021, is seeking a return to the White House after losing to Joe Biden in the 2020 election.
Harris has been serving as vice president since January 2021.
The election is expected to come down to a handful of battleground states -- Arizona, Georgia, Michigan, Nevada, North Carolina, Pennsylvania and Wisconsin.
CNN's early exit polls projected that Harris will win Massachusetts, Columbia, and Maryland. Trump is leading in Missouri, Oklahoma, Alabama, District of Columbia, Tennessee, Florida, West Virginia, Indiana and Kentucky.