As leaders around the world took their turn to welcome newly sworn-in US President Joe Biden and Vice-President Kamala Harris, some couldn’t resist the opportunity to aim a parting shot at Donald Trump.

Mr Biden was sworn in Wednesday (US time) as the 46th United States President, taking the reins of a country mired in crisis.

But he also faces a daunting task on the global stage, as he seeks to mend relations that have been bruised by the bruising, often confrontational style of his predecessor.

Leaders reacted to Mr Biden’s inauguration by offering congratulations, competing for position at the forefront of his foreign policy agenda, while many pleaded for the reversal of his predecessor’s policies.

There was a palpable sense of relief in many of the messages to Mr Biden, many of whom wearied of Mr Trump’s hyper-nationalist “America first” agenda.

• Pray for US as radical Christian right vies for power

None more so than the European Union’s top politician, Ursula von der Leyen, who said that “after four long years, Europe has a friend in the White House.”

Many others expressed hope that Mr Biden would right the world’s largest democracy after they watched rioters storm the US Capitol, shaking the faith of those fighting for democracy in their own countries.

German Chancellor Angela Merkel praised the swearing-in ceremony as “a true celebration of American democracy”.

“I look forward to a new chapter of German-American friendship and co-operation,” tweeted her spokesman Steffen Seibert, who quoted the chancellor on Twitter.

Tweet from @RegSprecher

Canadian Prime Minister Justin Trudeau, who butted heads with Mr Trump over trade, said that “Canada and the United States enjoy one of the most unique relationships in the world”.

Tweet from @JustinTrudeau

He said he looked forward to working with the new administration to promote climate action, clean economic growth, inclusion and diversity.

French President Emmanuel Macron noted the urgency of addressing climate change after Mr Trump withdrew the US from the Paris climate accord, a move Mr Biden reversed in the first hours of his presidency.

“We will be stronger to face the challenges of our time. Stronger to build our future. Stronger to protect our planet,” he wrote on Twitter.

“Welcome back to the Paris Agreement!”

Tweet from @EmmanuelMacron

NATO Secretary General Jens Stoltenberg called Wednesday “the start of a new chapter”.

The 70-year-old Western military alliance was shaken by Mr Trump’s frequent criticism, who often cast it as a drain on US resources.

British Prime Minister Boris Johnson, who appeared to have a chummy relationship with Trump, congratulated Mr Biden “on being sworn in as President of the United States” and Ms Harris “on her historic inauguration” on Twitter.

Tweet from @BorisJohnson

In Brussels, top EU officials welcomed a new era of co-operation with Washington after four years of often being treated like a hostile ally.

“Like people of all nations, the American people deserve leaders who take their hopes and concerns to heart,” EU Council President Charles Michel said, adding he trusted Biden and Harris to do “just that”.

Larry Hackett: Now, the real repair work begins

Italian Prime Minister Giuseppe Conte tweeted “this is a great day for democracy, reaching far beyond the American borders”.

Brazilian President Jair Bolsonaro, an ally of Mr Trump’s, congratulated Mr Biden and said he hoped the two countries could pursue a free-trade deal, in a letter posted on Twitter.

Japanese Prime Minister Yoshihide Suga congratulated Mr Biden and Ms Harris and said he looked forward to “working with you and your team to strengthen our alliance and realise a free and open Indo-Pacific”.

Israeli Prime Minister Benjamin Netanyahu, who enjoyed a warm relationship with Mr Trump, also voiced optimism.

“I look forward to working with you to further strengthen the US-Israel alliance, to continue expanding peace between Israel and the Arab world and to confront common challenges, chief among them the threat posed by Iran,” he said.

Tweet from @netanyahu

The Palestinians, meanwhile, hope Washington will dial down its pro-Israel stance.

Palestinian President Mahmoud Abbas expressed his readiness for “a comprehensive and just peace process that would achieve the wishes of the Palestinian people in freedom and independence.”

Biden’s to-do list starts now

Other nations also expressed cautious hope for a reset in relations before the inauguration.

China was hoping for “a collaboration beneficial to both sides”, the foreign ministry in Beijing said, adding the country would maintain its own interests and would not be defamed by the US.

Meanwhile, arch-rival Iran said it was ready to clear its differences with the US. But the ball was in Washington’s court, President Hassan Rouhani told state television on Wednesday.

Of the 2015 nuclear deal, Mr Rouhani said if Mr Biden was serious about fulfilling its international obligations towards Iran, Tehran would do likewise.

Pope Francis wished Biden – a devout Catholic – strength and wisdom.

“May Americans, under their leadership, continue to draw strength from the high political, ethical and religious values that have inspired the nation since its inception,” he wrote in a message to the White House.

Mr Biden has been quick to reverse many of the signature policies of the Trump administration.

One of his first acts as President was to sign a raft of executive orders, reversing a number of policies, with particular focus on immigration, climate change, racial equality and coronavirus.

The moves included an order requiring masks and physical distancing in all federal buildings and the development of a testing program for federal employees for COVID-19.

The order is a first step to combat a pandemic that has claimed the lives of more than 400,000 Americans.

-with agencies