G7 leaders launched a plan to help build infrastructure in poorer nations, offering a "values-driven, high-standard and transparent" partnership in opposition to China's Belt and Road Initiative.
The adoption of the US-inspired "Build Back Better World" (B3W) project came after President Joe Biden and leaders met to address "strategic competition with China and commit to concrete actions to help meet the tremendous infrastructure need in low- and middle-income countries", the White House said.
Meanwhile, Britain praised a "historic" action plan by G7 nations to prevent future pandemics.
The "Carbis Bay Declaration" - named after the seaside town in Cornwall, southwest England, where US President Joe Biden and other leaders are meeting this weekend - comprises a series of health policy commitments.
The collective steps include slashing the time taken to develop and license vaccines, treatments and diagnostics for any future disease to under 100 days, while reinforcing global surveillance networks.
It will be formally published Sunday, alongside the G7's final communique
"The #CarbisBayDeclaration marks a proud and historic moment for us all," Mr Johnson said on Twitter, as world leaders kicked off the second day of their three-day summit.
"Under this agreement, the world's leading democracies will commit to preventing a global pandemic from ever happening again, ensuring the devastation caused by COVID-19 is never repeated."
World Health Organization chief Tedros Adhanom Ghebreyesus, criticised in some quarters for being too accommodating towards China where the coronavirus originated, welcomed the health pact.
And he said the UN agency would examine a British proposal to create a "Global Pandemic Radar" to send early warnings of future outbreaks.
Britain's Queen Elizabeth II joins G7 leaders for a group photo. Source: AAP
"The world needs a stronger global surveillance system to detect new epidemic and pandemic risks," Tedros said.
However, aid charity Oxfam said the declaration "does nothing to address the fundamental problems that are preventing vaccines being accessible to the vast majority of humanity".
'Genocide' in China
The G7 - Britain, Canada, France, Germany, Italy, Japan and the United States - are largely focussed on "building back better" after Covid-19 wrecked economies and claimed millions of lives around the world.
They are expected to pledge to donate one billion vaccine doses to poor countries this year and next -- although campaigners say the rollout is much too slow to end the crisis sooner.
The leaders are also set to issue new commitments on climate change, including financial aid for the developing world, in the buildup to the UN's COP26 environmental summit in Scotland in November.
The agenda broadened Saturday to foreign policy issues, as the G7 was joined by the leaders of Australia, South Africa and South Korea, with India taking part remotely.
Biden is expected to press allies to bolster cooperation in dealing with a resurgent China, from offering an alternative to its trillion-dollar "Belt and Road" infrastructure initiative to confronting its alleged forced labour practices including against the Uyghur minority.
Prime Minister Boris Johnson (right) and French President Emmanuel Macron, ahead of a bilateral meeting during the G7 summit in Cornwall. Source: AAP
"This is not just about confronting or taking on China," a senior White House official said. "This is about providing an affirmative, positive alternative vision for the world."
He said Biden would be urging "concrete action" on the forced labour accusations, calling them "an affront to human dignity, and an egregious example of China's unfair economic competition".
China denies allegations that it is waging "genocide" by forcing up to one million Uyghurs and people from other ethnic-Turkic minorities into internment camps in the region of Xinjiang.
Northern Ireland
The US president will also seek to address frayed relations with Moscow, in particular over its cyber activity.
Most of the G7 leaders will reconvene Monday in Brussels for a NATO meeting, before Biden heads on to his first summit with Russian President Vladimir Putin in Geneva, vowing to deliver a blunt message about Russian behaviour.
In a rare interview with US media released Friday, Putin voiced hope that Biden would be less impetuous than Donald Trump, who infamously sided with the Russian leader against the views of his own intelligence chiefs.
"It is my great hope that, yes, there are some advantages, some disadvantages, but there will not be any impulse-based movements on behalf of the sitting US president," Putin told NBC News.
Closer to home for the G7 hosts, Johnson came under concerted pressure in separate meetings with the leaders of France, Germany and the European Union to respect his Brexit commitments over Northern Ireland.
"The prime minister expressed confidence in the UK's position in the Northern Ireland Protocol," a defiant Downing Street responded, referring to special Brexit arrangements for the restive province.
"He made clear his desire for pragmatism and compromise on all sides but underlined that protecting the Belfast Good Friday (peace) Agreement in all its dimensions was paramount."
