Joe Biden says 'clumsy' US triggered submarine row with France

US President Joe Biden was on Friday called a "good Catholic" by Pope Francis, at the start of a European trip in which he also sought to end a bitter diplomatic row with France by admitting that his country had been "clumsy" in its dealings with Paris.

Arriving at the Vatican for a papal meeting that lasted more than an hour -- longer than his two predecessors were given -- Biden kicked off a European tour aimed at pushing his mantra that "America is back" after Donald Trump's bruising years in the White House.

Biden, only the second Catholic to hold his office, said Francis had expressed pleasure that "I was a good Catholic" in the talks, which sidestepped the controversial topic of abortion.

The US president, who was due to attend a weekend G20 summit in Rome followed by marathon UN climate talks in Glasgow, later held his first talks with French President Emmanuel Macron since a row over a submarine deal worth tens of billions of euros.

"What we did was clumsy, it was not done with a lot of grace," Biden said, offering a public mea culpa over Washington's behaviour towards one of its oldest allies.

Paris reacted with fury last month to the announcement of a new US-UK-Australia deal which killed Australia's pre-existing agreement with France.

Biden's earlier talks with the pope were behind closed doors but footage released by the Holy See showed a good-humoured gathering full of smiles, with the president at points visibly moved, and elsewhere telling the pope "God love ya".

He called the pontiff "the most significant warrior of peace I have ever met", as he gave him a presidential coin recalling the regiment in which his son Beau Biden, who died from cancer in 2015, had served.

"I know my son would want me to give this to you," Biden said.

The president, who is open about his faith and how it gives him strength, has already met Francis three times before but this was their first tete-a-tete since he entered the White House.

Biden will travel to Glasgow for COP26 climate talks after the weekend G20 meeting.

Both Biden and the pope have been outspoken on the need to tackle global warming and this was a dominant theme of their talks.

"I thanked His Holiness for his advocacy for the world's poor and those suffering from hunger, conflict, and persecution, and lauded his leadership in fighting the climate crisis and ending the pandemic," the president tweeted.

The Vatican said they discussed climate change, the pandemic and the issue of refugees and migrants, as well as "the protection of human rights, including freedom of religion and conscience".

Following the meeting, which his wife Jill attended part of, Biden told journalists that the red-button issue of abortion was not discussed.

"We just talked about the fact that he was happy I was a good Catholic," Biden said.

Biden supports the right to choose, while Francis, 84, has called terminating pregnancies "murder".

The pontiff has nonetheless distanced himself from a push by conservative US bishops to deny communion to politicians supportive of abortion rights -- which would include Biden.

Shortly before leaving Washington, Biden unveiled a "historic" blueprint for remaking America's economy, a $1.75 trillion Build Back Better social welfare package on which he has staked his domestic legacy.

He had hoped to secure the deal before leaving, but it has been dogged by weeks of internal party feuding -- it remains to be seen if the revamped deal will gain the support of lawmakers.

After Trump's bruising diplomacy, Biden is hoping to reassert US global leadership, including in speaking up for democracies against regimes such as China, and on climate change.

Ahead of the crucial COP26 summit starting on Monday, Biden said his new plan includes "the most significant investment to deal with the climate crisis ever" -- $550 billion to cut greenhouse gas emissions.

"America is back in a leadership position on climate in a way that will be broadly welcomed," National Security Advisor Jake Sullivan told reporters on the flight over.