Biden, at the U.N., calls for unity in addressing the pandemic and climate change

NEW YORK — President Joe Biden made a case Tuesday that the United States can compete with China economically and ideologically while cooperating to confront global threats such as climate change and the coronavirus, as he tried to reassure allies with growing qualms about American leadership.

In his first address to the United Nations as president, Biden also defended the messy end to nearly two decades of war in Afghanistan, affirmed U.S. support for the United Nations and an alphabet soup of international partnerships and pledged support for poorer countries often disproportionately affected by climate change.

"We've ended 20 years of conflict in Afghanistan and as we close this era of endless war we are opening an era of endless diplomacy," Biden said in a measured address notable mostly for its contrast to the boastful tone and sour reception accorded President Donald Trump.

Challenges that require a united response include "ending this pandemic, addressing the climate crisis, managing shifts in global power dynamics, shaping the role of the world on vital issues like trade, cyber and emerging technologies and facing the threat of terrorism as it stands today," Biden said.

Biden was meeting with Australian Prime Minister Scott Morrison later Tuesday, less than a week after the surprise announcement that Australia would purchase U.S.-made nuclear submarines, a major military challenge to China in its Pacific neighborhood. The arrangement infuriated France, which had contracted to provide less capable ships, with French officials claiming they were blindsided.

The fence-mending follows several setbacks for Biden as he tries to rebuild trust among allies after four years of Trump. European allies have grown increasingly skeptical about Biden's message that "America is back" in light of an Afghanistan withdrawal that left NATO nations feeling sidelined and as he advances a China agenda many find needlessly confrontational.

Biden persuaded ambivalent allies to take a slightly tougher public line against China over human rights and economic practices during his first trip abroad, in June. But he has gotten little public backing for his broader argument that China could pose an existential threat to democratic governments in the future, and that old conflicts such as Afghanistan are a distraction.

"The world of today is not the same world as 2001," Biden said of the year the Afghan conflict began in response to the terrorist attacks of Sept. 11.

Biden entered the gathering of global leaders shadowed by the new breach with ally France, whose foreign minister has openly questioned whether Biden really represents a change from Trump, who distrusted traditional alliances and rejected consensus.

"We can only acknowledge that this spirit is still the same," as under Trump, Jean-Yves Le Drian told reporters Monday.

"A basic principle among allies is we talk to one another. We can't hide and put together some alternative strategies. This is surprising and shocking; this is why there is a crisis of trust beyond the fact that the contract is being broken."

» READ MORE: Biden confronts extreme heat, a silent climate killer

The concern among European leaders that Biden is taking a go-it-alone approach includes the withdrawal from Afghanistan, he said. Several NATO allies opposed the Aug. 31 withdrawal deadline Biden set but felt powerless to argue against it. Others grumbled that the United States didn't have sufficient plans in place when the moment came, leading to scenes of chaos as foreigners and vulnerable Afghans rushed to flee a Taliban takeover.

Europeans have also raised alarm of a refugee crisis or terrorism arising from the collapse of the Western-backed government in Afghanistan.

"The Europeans should not be left behind in a strategy chosen by the United States," Le Drian said.

French President Emmanuel Macron temporarily recalled his ambassadors to the United States and Australia in protest, an unprecedented breach between Washington and Paris that left the White House scrambling. Biden and Macron are expected to speak by phone this week.

Biden returns to Washington later Tuesday, where he is slated to host British Prime Minister Boris Johnson at the White House. The populist Johnson was a Trump favorite for his successful effort to withdraw Britain from the European Union. His relationship with Biden is businesslike but cooperative as Britain prepares to host a marquee climate summit in November.

Biden pledged to work with Congress to seek additional funding.

Even as it has embraced more aggressive action to cut emissions under Biden, the United States has faced criticism for not doing more to pay its fair share to help more vulnerable countries battered by climate change.

In April, the Biden administration in promised to double its annual climate financing to developing countries by 2024, to $5.7 billion — a figure some critics said was too paltry given the U.S. role as the world's largest historical emitter of greenhouse gases.

"I can assure you that we're looking for ways to go even further toward meeting the collective goal of mobilizing $100 billion a year," Biden vowed Friday at a virtual gathering of leaders from major economies.

» READ MORE: The House to vote on government funding and debt as the GOP digs in

As the U.N. event in Scotland approaches, world leaders have faced intense pressure to commit to more concrete, ambitious, near-term plans to cut greenhouse gas pollution in coming years.

Collectively, the world remains far off target from the goals of the 2015 Paris climate agreement and remains on a trajectory that scientists and many policymakers alike have described as "catastrophic."

Trump pulled the United States out of the Paris compact; Biden won goodwill among major allies for rejoining it as one of his first actions as president.

But distrust and exasperation persist among small, developing nations that have done little to cause climate change but often have been most ravaged by its impacts.

Developed countries pledged more than a decade ago to begin providing $100 billion annually by 2020 to help the most defenseless nations deal with the deepening consequences of sea-level rise, heat waves, intensifying hurricanes and other effects of warming — and to hasten the transition away from fossil fuels as those economies grow.

That money has never fully materialized.

According to an updated analysis this month from the Organization for Economic Cooperation and Development, or OECD, developed nations mobilized $79.6 billion in 2019 to help poorer countries grapple with climate change — a 2% increase from the previous year, but still a $20 billion broken promise.

"Failure to fulfill this pledge would be a major source of the erosion of trust between developed and developing countries," U.N. Secretary General António Guterres told reporters on Monday. "Developed nations need to bridge this gap."

The Washington Post’s Brady Dennis contributed to this report from Washington.