US President Joe Biden is to urge Western countries to counter China's growing influence at the second day of the G7 summit, an aide told the BBC.
At the meeting in Britain, President Biden is expected to call for a new alliance to rival Beijing's spending on infrastructure in developing countries.
The US and its allies accuse China of forced labour and other human rights abuses in Xinjiang province.
G7 leaders will also commit to a new plan to stop future pandemics.
The measures include cutting the time needed to develop vaccines and treatments for Covid-19 to under 100 days.
UK Prime Minister Boris Johnson is hosting the three-day gathering at the seaside resort of Carbis Bay in Cornwall.
The Americans see Saturday's session at the G7 as being about challenging the rise of Chinese influence around the world. Beijing's Belt-and-Road initiative, which has seen billions of dollars poured into developing countries, must be countered by the Western democracies.
Senior administration officials want to prove that Western values can prevail. They argue that Chinese investment has come with too high a price tag; that the forced labour of the Uyghur minority in Xinjiang is morally egregious, and economically unacceptable as it prevents fair competition.
Global supply chains, Joe Biden will insist, must be free of this kind of labour. US officials say this is not just about confronting China, but about presenting a positive alternative for the world.
But the Biden administration has been vague about how much the West would contribute to this global infrastructure plan and over what timescale. What is clear is a renewed determination among Western powers that they need to act now to counter a resurgent and increasingly powerful China.