Leaders of the Group of 20 major economies began arriving on Monday at Rio de Janeiro's Modern Art Museum for their annual summit, bracing for a shift in the global order with the return to power of US president-elect Donald Trump.

Among them is President Xi Jinping, who arrived in Rio on Sunday for the summit and a state visit to Brazil.

Brazilian President Luiz Inacio Lula da Silva received the heads of government on a red carpet at the museum where they will meet through Tuesday.

Their discussions of trade, climate change and international security will run up against the sharp US policy changes that Trump vows upon taking office in January, from tariffs to the promise of a negotiated solution to the war in Ukraine.

Security has been strengthened with troops reinforcing police for the duration of the summit.

Xi has also been meeting with G20 leaders on the sidelines of the summit.

In talks with British Prime Minister Keir Starmer, the president said Beijing and London "should adopt a rational and objective perspective on each other's development," according to Xinhua News Agency, adding that the two countries should deepen political mutual trust to ensure the steady development of bilateral relations.

"We want our relations to be consistent, durable, respectful as we have agreed, avoid surprises where possible, and strengthened dialogue should provide stronger understanding," Starmer said.

This is the first meeting between the leaders of China and the UK since 2018.

Xi also met with Australian Prime Minister Anthony Albanese.

The president said "there is no fundamental conflict of interests between China and Australia."

Albanese said there had been "encouraging progress in the stabilisation of our relationship". (Reuters/Xinhua)