Donald Trump, Joe Biden to kick off first US presidential election rematch in 70 years

• Biden surpasses 1,968 delegates, Trump secures 1,215.
• Contests held in Georgia, Washington, other states.
• Biden faced opposition in Democratic primary campaign.

United States President Joe Biden and former president Donald Trump both won their parties' nomination on Tuesday, and will be kicking off the first US presidential election rematch in nearly 70 years.

Biden, on Tuesday, successfully passed the 1,968 delegates required for the nomination, as results from the primary contest in Georgia, Mississippi, Washington state, the Northern Mariana Islands, and Democrats living aboard began to emerge.

Meanwhile, Trump secured the 1,215 delegates needed for the Republican presidential nomination in four states, including Georgia, where he faces criminal charges for overturning the state's 2020 results.

The contests took place in Georgia, Hawaii, Mississippi and Washington.

Biden, 81, issued a statement after he sealed the Democratic nomination, taking aim at what he called Trump's "campaign of resentment, revenge, and retribution that threatens the very idea of America."

"Voters now have a choice to make about the future of this country. Are we going to stand up and defend our democracy or let others tear it down? Will we restore the right to choose and protect our freedoms or let extremists take them away?" he said.

In a video posted on social media, Trump said there was no time to celebrate, and instead put the focus on beating Biden, whom he called the "worst" president in US history.

"We're going to drill, baby, drill. We're going to close our borders. We're going to do things like nobody has ever seen before. And we're going to make our nation's economy be the best ever in the world," said Trump.

Biden also faced opposition in the Democratic primary campaign, but liberal activists' dissatisfaction with his support for Israel's genocide in Gaza led a significant minority of Democrats to vote "uncommitted" in protest.

Trump, 77, retorted his 2020 election fraud claim during his rally in Georgia and accused the Fulton County attorney, Fani Willis, of prosecuting him for political reasons.

He also criticised Biden for failing to curb the flow of migrants at the US southern border, an issue he plans to address throughout the campaign.