HANGZHOU (AFP) - Group of 20 leaders meet on Sunday (Sept 4) charged with reviving the sluggish world economy, but a growing anti-globalisation mood and alarm over China's territorial ambitions loom over the summit in the scenic city of Hangzhou.
China is hoping a successful meeting will portray it as an assured, powerful nation ready to assume a role on the international stage that befits its status as the world's second-largest economy.
In a promising opening act, Chinese President Xi Jinping and his United States counterpart Barack Obama ratified the Paris climate accord on Saturday (Sept 4), with clear blue skies over the city's largely empty streets.
To create that set, the authorities shuttered thousands of factories and encouraged residents to leave town on free holidays, as well as detaining dozens of dissidents to prevent any hint of unrest.
United Nations chief Ban Ki Moon, who personally received the ratification documents from Mr Xi and Mr Obama, applauded them on Sunday for "making this historic step" which represented "a major step forward" on tackling climate change.
He urged other G-20 leaders to follow suit and turn aspirational pledges into the "the transformative action the world so urgently needs".
But experts expect the gathering to be short on substance, as rising populist sentiment makes it difficult for leaders to commit to the kinds of measures needed to address the world's most pressing issues.
International Monetary Fund chief Christine Lagarde warned last week that the world faces a potentially toxic mix of low long-term growth and rising inequality, creating political temptations to populism and raised trade barriers.
In Hangzhou, geopolitical concerns - from rising tensions over the strategically vital South China Sea, to the ongoing Syrian civil war - also threaten to disrupt Beijing's carefully plotted script.
The hosts have been keen to avoid the contentious South China Sea topic, but international alarm is rising over Beijing's claims in the region where it has built artificial islands and facilities including airstrips on reefs and outcrops.
There were suggestions of a testy exchange between Mr Xi and Mr Obama on Saturday over a United Nations tribunal ruling which found there was no legal basis for Beijing's claims to the waterway.
"The two leaders had a candid exchange on the recent arbitral tribunal ruling on the case between the Philippines and China, with President Obama emphasising the importance for China... to abide by its obligations" the White House said in a statement.
The US has said it will continue naval patrols near the reefs and outcrops China claims to assert the principle of freedom of navigation, a move which has angered Beijing.
Mr Xi "urged the United States to 'play a constructive role' in maintaining peace and stability in the South China Sea", the official Xinhua news agency said.
But both countries are eager to avoid conflict in Hangzhou. A successful summit will boost Mr Xi's international and domestic billing as he heads towards a series of key Communist Party meetings.
And Mr Obama hopes a positive outcome will cement his legacy as he approaches the end of his run in office.
But there were wrinkles on Saturday when a shouting match broke out over access for reporters travelling with Mr Obama on the airport tarmac as Air Force One taxied across the runway.
"This is our country!" a Chinese official, in a dark suit, shouted at a White House staff member. "This is our airport!"
When US National Security Adviser Susan Rice and senior White House staff member Ben Rhodes tried to get closer to the President, the official also turned his ire on Ms Rice, prompting her Secret Service agent to step in.
Mr Obama took the fracas in his stride on Sunday, saying that although the US insists on press access and does not "leave our values and ideals behind", the travelling White House juggernaut could be intimidating.
"I think this time... the seams are showing a little more than usual in terms of some of the negotiations and jostling that takes place behind the scenes," he told a press conference.