ROME — President Biden capped an extended weekend of diplomacy on Sunday with a swaggering proclamation of America’s renewed power on the world stage, claiming credit score for what he solid as breakthroughs on local weather change, tax avoidance and Iran’s nuclear ambitions on the finish of a Group of 20 summit that was lacking a few of his largest international adversaries.

Buoyed by a three-day return to the interpersonal negotiations which have outlined his political profession and nonetheless overcome emotionally by an prolonged Friday audience with Pope Francis, Mr. Biden shook off questions on his sagging ballot numbers at dwelling and projected new optimism for his teetering home coverage agenda.

He acknowledged contradictions and obstacles to his long-term ambitions on points like decreasing greenhouse gasoline emissions with a smile. And he claimed important progress from a summit that produced one giant victory for his administration — the endorsement of a world pact to set minimal company tax charges — together with a deal between the US and Europe that may raise tariffs together with these on European metal and aluminum.

In different areas, like local weather change and restoring a nuclear accord with Iran, the summit produced few concrete actions.

However the president instructed reporters repeatedly that the weekend had proven the facility of American engagement on the world stage, and that it had renewed relationships that frayed beneath his predecessor, Donald J. Trump.

“They listened,” Mr. Biden stated. “Everybody sought me out. They wished to know what our views had been. We helped lead what occurred right here. The USA of America is probably the most important a part of this complete agenda and we did it.”

In the midst of his Roman vacation, Mr. Biden sought to patch up relations with the French over a soured submarine deal, to bask within the blessing of the tax deal that his administration pushed over the road after years of talks, and to provoke extra formidable local weather commitments forward of a global conference in Glasgow, Scotland, that he was touring to subsequent.

The president left behind the chaos and disappointments of Washington, the place current surveys present that voter disapproval is mounting over his efficiency in workplace and that Democrats stay divided over a pair of payments that may spend a mixed $3 trillion to advance his wide-ranging home agenda. Polling carried out by NBC News exhibits that seven in 10 Individuals and nearly half of Democrats consider America goes within the unsuitable course.

However after days of indulging in backslapping diplomacy at a time when bipartisan cooperation is briefly provide at dwelling, Mr. Biden emerged for his information convention on Sunday professing hope that each payments would move the Home within the subsequent week and taking part in down the polls.

“The polls are going to go up and down and up and down,” Mr. Biden stated. “Take a look at each different president. The identical factor has occurred. However that’s not why I ran.”

One motive Mr. Biden sought the presidency, after greater than 4 a long time as a senator and vice chairman, was for conferences just like the Group of 20, the place he is ready to follow the flesh-pressing politics he has lengthy loved.

World leaders have been gradual to reconvene in individual because the pandemic has stretched into its second yr, however Mr. Biden attended a Group of seven assembly in England in June that was a diplomatic icebreaker of kinds for rich international locations. The summit in Rome introduced a bigger group of leaders collectively, although a few of Mr. Biden’s largest rivals on the world stage, like China’s Xi Jinping and Russia’s Vladimir Putin, stayed dwelling.

Mr. Biden and different world leaders stated the return to in-person talks modified the dynamic.

Mario Draghi, the Italian prime minister whose nation hosted the summit, stated at a information convention that attendees had been extra keen than they’d been prior to now to deal with local weather change, inequality, and different issues that may require collective motion to repair.

“One thing modified,” Mr. Draghi stated.

Mr. Biden had hourlong conferences on the summit with leaders of various affect.

The prime minister of Singapore, Lee Hsien Loong, bought 80 minutes. On Sunday, Mr. Biden additionally met with President Recep Tayyip Erdogan of Turkey on the sidelines, rising with the shared promise to maintain participating on a spread of disagreements, largely in view of Turkey’s affect in a number of important areas, together with Syria, Afghanistan, Libya and the Japanese Mediterranean.

Mr. Biden stated there have been no substitutes for “ somebody straight within the eye whenever you’re making an attempt to get one thing executed.”

However in lots of areas, the summit produced extra rhetoric than motion.

An settlement reached by the leaders on Sunday pledged to finish the financing of coal energy vegetation in international locations exterior their very own and to “pursue efforts” to maintain the typical international temperature rise to 1.5 levels Celsius by the tip of this century.

“We stay dedicated to the Paris Settlement objective to carry the worldwide common temperature improve nicely beneath 2°C and to pursue efforts to restrict it to 1.5°C above preindustrial ranges,” the leaders stated in an announcement.

The dearth of additional progress angered activists and presaged the difficulties Mr. Biden may face when he attends a high-stakes local weather conference in Glasgow starting on Monday.

Mr. Biden conceded the irony in one other push he made on the summit — for oil- and gas-producing international locations to ramp up manufacturing to push down driving and heating prices — at a time when he’s additionally urging the world to show away from fossil fuels. However he stated that the transition from oil and gasoline to lower-emission alternate options wouldn’t occur instantly, and that he was in search of to insulate shoppers from value shocks within the meantime.

The summit’s local weather commitments drew fast criticism from environmental activists. Jennifer Morgan, the manager director of Greenpeace Worldwide, referred to as the settlement among the many leaders “weak,” and stated it “lacked ambition and imaginative and prescient.” Jörn Kalinski, a senior adviser at Oxfam, stated it was “muted, unambitious, and missing in concrete plans.”

Mr. Biden provided solely incremental progress on the problem of unsnarling international provide chains, which was the topic of a facet assembly of 14 international locations that he hosted Sunday afternoon. Mr. Biden introduced he was signing an government order on the protection stockpile that may “enable us to react and reply extra rapidly to shortfalls” in provide chains.

He additionally unveiled a deal to roll again tariffs on European metal and aluminum, an accord between the US and the European Union that he stated would profit American shoppers and “show to the world that democracies are taking up onerous issues and delivering sound options.”

There have been no resolutions over a protracted dispute about Turkey’s buy of the Russian S-400 air protection system. Mr. Erdogan has refused to step again from the acquisition, regardless of sanctions and expulsion from a U.S. protection program to develop the F-35 stealth fighter jet. And Mr. Biden didn’t agree to permit Mr. Erdogan to buy F-16 fighter jets to replace its fleet with cash it had already spent for the F-35s.

However as his information convention wound down, the engagement Mr. Biden lingered on longest was the one which kicked off his journey: his assembly with Pope Francis.

Requested by a reporter about criticism from some conservative American Catholics that public officers like Mr. Biden, who’re Catholic however assist authorized entry to abortion, ought to be denied communion, Mr. Biden stated the problem and his assembly with the pope had been “private.”

The pope, Mr. Biden had stated on Friday, referred to as him a “good Catholic” and stated he ought to proceed to obtain communion.

On Sunday, Mr. Biden launched into an extended reflection on his relationship with Francis, and his admiration for him. He recounted how the pope had endorsed his household after the loss of life of Mr. Biden’s eldest son, Beau, a tragedy he equated with shedding “an actual a part of my soul.”

Choking up at moments, Mr. Biden stated the pope had grow to be “somebody who has offered nice solace for my household when my son died.”

The 2 males, Mr. Biden added, keep up a correspondence.

He walked off the stage, taking no additional questions.

Carlotta Gall, Jason Horowitz, and Somini Sengupta contributed reporting.