Both US President Joe Biden and former President Donald Trump have secured their parties' nominations for the November election by surpassing the delegate thresholds.

On Tuesday, primaries were held in four states, one American territory, and among Democrats living abroad, setting the stage for a rematch of the 2020 presidential election in November.

The nominations will be officially confirmed at the party conventions later this summer. President Joe Biden, 81, expressed gratitude for the support, emphasizing the urgency to counter the perceived threat posed by his predecessor, Donald Trump, 77.

Biden highlighted economic progress while acknowledging challenges to democracy, including efforts to restrict abortion rights and cut social programs. Despite concerns about his age, Biden faced no significant challengers within the Democratic Party, benefiting from the support of party leaders.

Meanwhile, Trump remains popular among Republican voters, focusing his campaign on promises of stricter immigration laws, enhanced border security, crime reduction, energy independence, and a nationalist foreign policy stance.

While both candidates have dominated their respective primaries, dissatisfaction among Americans looms over the prospect of another Biden-Trump showdown in November, despite the inevitability of their re-nominations.

The Democratic and Republican parties follow similar procedures for their primaries, with each state allocated a specific number of party delegates. These delegates are awarded either winner-takes-all or proportionally, depending on the state's rules.

For Republicans, securing a minimum of 1,215 delegates is necessary to win the presidential nomination, while Democrats need to secure 1,968 delegates.

In recent primary contests, Republicans held primaries in Mississippi, Georgia, and Washington State, along with a caucus in Hawaii. Democrats, on the other hand, held primaries in Georgia, Washington, and Mississippi, in addition to contests in the Northern Mariana Islands and among Democrats residing abroad.

The main competitors of both President Joe Biden and former President Donald Trump had dropped out of the race before Tuesday's primaries, making the outcomes largely predictable. For instance, former UN Ambassador Nikki Haley, Trump's last remaining challenger, withdrew earlier this month after losing numerous states to Trump on Super Tuesday.

Even though several states are yet to conduct their primary contests, with both Trump and Biden having surpassed the delegate threshold, the race for the 2024 general election is now effectively underway.

The US presidential election is scheduled for November 5, 2024.