The G7 group of rich nations has agreed plans to set up an alternative to China’s belt and road initiative as part of a broad push back against Beijing covering human rights, supply chains, support for Taiwan and demands to reveal more about the origins of the Covid-19 pandemic.

Some G7 leaders, however, including the Italian prime minister, Mario Draghi, the current chair of the G20, have urged Joe Biden not to push competition with China to the extent that it prevents cooperation on other vital issues such as the climate crisis.

The EU is also pressing the US to back a legally binding code of conduct for the South China Sea that Beijing has been negotiating with regional powers.

US officials said Biden was pushing the other G7 leaders for “concrete action on forced labour” in China and to include criticism of Beijing in their final communique. Japan also said it was backing a mention of Taiwan in the final statement.

The US secretary of state, Antony Blinken, spoke to his Chinese opposite number, Yang Jiechi, from Cornwall on Friday to urge him to release more details about whether Covid-19 leaked from a Wuhan laboratory, a once-dismissed theory now gaining currency.

Small-circle diplomacy is a caustic reference to the fact that the proportion of GDP generated by G7 states has declined. Boris Johnson, the prime minister of the UK, the summit’s host nation, is however widening that circle by inviting the leaders of the chief democracies in Asia and the Pacific region – India, Australia and South Korea – to come to the talks in Cornwall this weekend.

Biden raised the ideaof reviving a Trump-era plan for democratic countries to develop their own rival scheme with Johnson in March.

In discussions at the G7, Biden also pressed other leaders to make clear that they believe forced labour was an affront to human dignity and “an egregious example of China’s unfair economic competition” to show that they were serious about defending human rights.

“We’re pushing on being specific on areas like Xinjiang where forced labour is taking place and where we have to express our values as a G7,” the US official said of the final communique to be issued at the end of the summit on Sunday.

It is not clear if the wording will be tougher than the G7 foreign ministers’ statement in May that said: “We agree the importance of tackling instances of forced labour through our own available domestic means, including through raising awareness and providing advice and support for our business communities. We strongly support independent and unfettered access to Xinjiang to investigate the situation on the ground.”

The communique also implicitly recognised Taiwan’s independence by calling for it to attend the World Health Organization and World Trade Organization.