Washington (AFP) - US President Joe Biden will give what could be his final Oval Office speech Wednesday to explain why he dropped out of November’s election and deny that he will spend six months as a lame duck.

With the world’s eyes already on a looming clash between Vice President Kamala Harris and Donald Trump, Biden will insist that he still has work to do, despite his historic decision to bow out.

The 81-year-old Democrat said on X he would discuss “what lies ahead, and how I will finish the job for the American people” in the primetime televised event at 8:00 pm (0000 GMT Thursday).

The speech, expected to last eight to ten minutes, will be Biden’s first since stepping aside from the race on Sunday after weeks of pressure following a disastrous debate performance against Trump.

He had promised in his withdrawal announcement – made while he was isolating with Covid at his Delaware beach home – that he would give Americans more details on his stunning decision.

It comes just over a week since his last Oval Office address, following an assassination attempt against Trump on July 13, but is only the fourth of his presidency overall – and could well be his last.

With Harris, who has effectively clinched the Democratic presidential nomination, and Trump both back on the campaign trail, Biden will be fighting an uphill battle to show Americans he is not yesterday’s man.

Republicans have called for Biden to step down altogether, saying that if he is not fit to stand for reelection then he is not fit to serve as president.

The veteran Democrat insists he still has much to offer, with a particular focus on the economy and on achieving an elusive ceasefire in Israel’s war against Hamas in Gaza.

- ‘Not going anywhere’ -

Biden, who meets Israeli Prime Minister Benjamin Netanyahu at the White House on Thursday, has said that they are on the verge of reaching a ceasefire in Gaza.

He would not be the first US president to chase a legacy-defining Middle East peace deal, after Jimmy Carter, Bill Clinton and even Donald Trump before him.

But in a sign of how quickly things are already moving on, Netanyahu will sit down separately Thursday with Harris – who was skipping his address to Congress on Wednesday due to a previously scheduled campaign trip.

Trump, meanwhile, said in a post on Truth Social that he will meet with the Israeli leader Friday at the Republican’s Mar-a-Lago resort in Florida.

With the clock ticking on his presidency, Biden said on X late Tuesday that it was “great to be back at the White House” after returning from Delaware, and that he had met his national security team for a briefing.

His decision to drop out has injected a huge dose of enthusiasm into a Democratic Party that had been plunged into chaos by the debate over his age.

An exuberant Harris was cheered to the rafters on Tuesday as she held a campaign rally in the battleground state of Wisconsin, her first since saying she had secured the delegates necessary for the nomination.

She could be nominated as soon as early August in a virtual vote by Democratic delegates ahead of the party’s convention in Chicago just over two weeks later.

For Harris the challenge will now be to maintain that enthusiasm – and then to translate it into ballot box success in November.

Trump is due to appear in Charlotte later Wednesday for his first rally since Harris became the de facto nominee.

He is expected to ramp up his attacks on her, as at least one national poll conducted after Biden’s exit showed Harris slightly ahead.

Meanwhile, the impact of Biden’s decision on Americans unenthused by the long slog between him and Trump was coming more into focus.

Non-profit voter registration group Vote.org said Wednesday that it had registered nearly 40,000 voters in the 48 hours after Biden’s bombshell announcement, an almost 700 percent daily increase.

“That’s the largest number of new voters registered over a 48 hour period we’ve seen this entire cycle,” posted Vote.org CEO Andrea Hailey on X.