US President Joe Biden on Tuesday formally announced that he is running for re-election in 2024, asking voters to give him more time to “finish the job” he began when he was sworn in to office and to set aside their concerns about extending the run of America’s oldest president for another four years.

Biden, who would be 86 at the end of a second term, is betting his first-term legislative achievements and more than 50 years of experience in Washington will count for more than concerns over his age. He faces a smooth path to winning his party’s nomination, with no serious Democratic rivals. But he’s still set for a hard-fought struggle to retain the presidency in a bitterly divided nation.

The announcement, in a three-minute video, comes on the four-year anniversary of when Biden declared for the White House in 2019, promising to heal the “soul of the nation” amid the turbulent presidency of Donald Trump – a goal that has remained elusive.

“I said we are in a battle for the soul of America, and we still are," Biden said. “The question we are facing is whether in the years ahead we have more freedom or less freedom. More rights or fewer.”

While the question of seeking re-election has been a given for most modern presidents, that’s not always been the case for Biden, as a notable swath of Democratic voters have indicated they would prefer he not run, in part because of his age – concerns Biden has called “totally legitimate” but ones he did not address head-on in the launch video.

Yet few things have unified Democratic voters like the prospect of Trump returning to power. And Biden’s political standing within his party stabilised after Democrats notched a stronger-than-expected performance in last year’s midterm elections, as the president set out to run again on the same themes that buoyed his party last fall, particularly on preserving access to abortion.

“Freedom. Personal freedom is fundamental to who we are as Americans. There’s nothing more important. Nothing more sacred,” Biden said in the launch video, which painted the Republican Party as extremists trying to roll back access to abortion, cut Social Security, limit voting rights and ban books they disagree with. “Around the country, MAGA extremists are lining up to take those bedrock freedoms away.”

“This is not a time to be complacent,” Biden added. “That’s why I’m running for re-election."

As the contours of the campaign begin to take shape, Biden plans to campaign on his record. He spent his first two years as president combating the coronavirus pandemic and pushing through major bills such as the bipartisan infrastructure package and legislation to promote high-tech manufacturing and climate measures.

With Republicans now in control of the House, Biden has shifted his focus to implementing those massive laws and making sure voters credit him for the improvements, while sharpening the contrast with the GOP ahead of an expected showdown over raising the nation's borrowing limit that could have debilitating consequences for the country's economy.

But the president also has multiple policy goals and unmet promises from his first campaign that he’s pitching voters on giving him another chance to fulfill.

“Let’s finish this job. I know we can,” Biden said in the video, repeating a mantra he said a dozen times during his State of the Union address in February, listing everything from passing a ban on assault-style weapons and lowering the cost of prescription drugs to codifying a national right to abortion after the Supreme Court's ruling last year overturning Roe v. Wade.

As a candidate in 2020, Biden pitched voters on his familiarity with the halls of power in Washington and his relationships around the world as he promised to return a sense of normalcy to the country amid Trump’s tumultuous presidency and the deadly Covid-19 pandemic.

But even back then, Biden was acutely aware of voters’ concerns about his age.

“Look, I view myself as a bridge, not as anything else,” Biden said in March 2020, as he campaigned in Michigan with younger Democrats, including now-Vice President Kamala Harris, Senator Cory Booker of New Jersey and Michigan Governor Gretchen Whitmer. “There’s an entire generation of leaders you saw stand behind me. They are the future of this country.”

Three years later, the president now 80, Biden allies say his time in office has demonstrated that he saw himself as more of a transformational than a transitional leader.

Still, many Democrats would prefer that Biden didn’t run again. A recent poll from The Associated Press-NORC Centre for Public Affairs Research shows just 47 percent of Democrats say they want him to seek a second term, up from 37 percent in February. And Biden’s verbal – and occasional physical – stumbles have become fodder among the GOP, which has sought to cast him as unfit for office.

Biden, on multiple occasions, has brushed back concerns about his age, saying simply, “Watch me.” (AP)