Trump takes oath
Donald Trump is sworn into office by Supreme Court Chief Justice John Roberts as Melania Trump holds the Bible in the U.S. Capitol Rotunda on January 20, 2025 in Washington, DC. Donald Trump takes office for his second term as the 47th president of the United States. Saul Loeb - Pool/Getty Images

Donald Trump was sworn in for a historic second term as president Monday, promising a new "golden age" for America as the world braces for a return of his unpredictable leadership.

Freezing weather has forced the 78-year-old's inauguration at the US Capitol indoors, but the first hours of the most extraordinary comeback in American politics will be a blaze of activity.

The Republican vowed to unleash a blitz of executive orders undoing Joe Biden's legacy upon his return to the White House, and to launch immediate deportations of undocumented migrants.

If Trump painted a dystopian picture of "American carnage" at his first inauguration in 2017, this time around he is offering a more upbeat promise of a "brand new day" for the United States.

"I will act with historic speed and strength and fix every single crisis facing our country," Trump told a huge inauguration eve rally where he also danced with the Village People band.

But the billionaire populist also returned to some of the dark themes that drove his election victory over Democratic Vice President Kamala Harris in November.

The incoming 47th US president said he would "stop the invasion of our borders" and reverse "woke" policies including "transgender insanity" in US schools.

Trump made history by replacing Biden as the oldest president to be sworn in. He is also just the second president in US history to return to power after being voted out, after Grover Cleveland in 1893.

Ahead of the inauguration, Biden and First Lady Jill Biden hosted Trump and his wife Melania for "tea and coffee" at the White House, before they all traveled to the Capitol.

The display of civility was a stark contrast to 2021 when Trump -- who riled a crowd that attacked the US Capitol in a bid to overturn his election loss -- refused to attend Biden's inauguration.

Trump's triumphal mood has meanwhile not been chilled by the fact that the swearing-in on the steps of the Capitol had to be moved due to predictions of the coldest Inauguration Day for 40 years.

Instead of taking the oath in front of a huge crowd on the National Mall, Trump and Vice President-elect J.D. Vance did so inside the domed Rotunda of the Capitol, as Ronald Reagan did in 1985.

There are still many Americans concerned by Trump's darker promises -- the vows of retribution against his political opponents and journalists.

Trump returns to the Oval Office more powerful than ever, capping a journey that saw him defy two assassination attempts and a criminal conviction to win the election.

Once a political outsider, Trump has become the new normal for US politics.

Three of the world's richest men -- tech tycoons Elon Musk, Mark Zuckerberg and Jeff Bezos -- were alongside Trump for the inauguration.

Tesla, SpaceX and X boss Musk, who will head a cost-cutting effort in the new administration, promised at Sunday's rally to make America strong "for centuries."

Trump -- who said during the election campaign he would only be a dictator on "day one" -- has promised to sign around 100 executive orders within hours of taking office.

They include declaring a national emergency on the southern US border with Mexico, and undoing the Biden administration's directives on diversity and oil drilling.

Trump added that supporters would be "very happy" with a decision pardoning January 6 rioters.

For the rest of the world, Trump's return means expecting the unexpected.

From promising sweeping tariffs, to making territorial threats to Greenland and Panama and calling US aid for Ukraine into question, Trump looks set to rattle the global order once again.

His victory has also emboldened right-wing politicians around the world. Italy's far-right Prime Minister Giorgia Meloni is set to attend the inauguration even though foreign leaders are not normally invited.

Trump's inauguration has been moved indoors at the US Capitol due to freezing weather
Trump's inauguration has been moved indoors at the US Capitol due to freezing weather AFP