US President-elect Donald Trump's projected win in Arizona against Democratic candidate Kamala Harris has earned him a big victory in the November 5 election.

The win also means Trump has swept all seven battleground states in addition to the states he was certain to win in pre-election projections.

ABC News projected on Saturday that President-elect Trump will carry the western US state, which was the last in the country to report the results.

With a win in Arizona, Trump won 312 electors, well above 270 needed to win, against Harris' 226.

The AP news agency says Trump had garnered 74,644,300 votes while Harris had won 70,910,573 votes. That's as of Saturday evening.

If the vote count settles along this line, popular votes for a Republican presidential candidate would outnumber those for their Democratic rival for the first time in 20 years.

US media attribute Trump's victory to his campaigning on inflation and immigration issues in the country that many voters are frustrated with.

In the Congressional race, which also took place on November 5, the Republicans are set to retake a majority in the Senate.

Attention is focused on whether the Republicans will hold onto their majority in the House to complete a Red Shift in the presidency and both Houses of Congress.