Rishi Sunak will call for a “frank and constructive relationship” with China during a meeting with the country’s President Xi Jinping at the G20 summit.
It is the first time a UK prime minister has met the Chinese president in person since 2018.
No 10 said China had “fundamentally different values to ours”.
But it said issues like the Ukraine war could not be addressed without “co-ordinated action by the world’s major economies”, including China.
Leaders of the world’s biggest economies are meeting in Bali, Indonesia, to discuss global challenges including the economic recovery from the Covid pandemic and the impact of the Russian invasion of Ukraine.