Trump heads to G20 primed for new conflicts

US President Donald Trump jets to Argentina Thursday for a G20 summit, keen to do battle with China on trade and sharpening his rhetoric over Ukraine against Russia ahead of a meeting with its leader Vladimir Putin.

The weekend summit is confronted with increasingly dire warnings, by the International Monetary Fund among others, of the potential harm faced by the world economy from Trump's trade wars.

G20 leaders, whose countries account for four-fifths of the world's economic output, first met in November 2008 to forge a united front against the global financial crisis.

A decade on, that unity has vanished as the "America First" Trump shreds the consensus underpinning international trade and other G20 countries such as Brazil, Italy and Mexico turn to populist leaders.

Trump has already rattled global markets by enacting tariffs on the bulk of Chinese imports, and is threatening to go further in January.

He will press Chinese President Xi Jinping to avert the stepped-up tariffs by throwing open China's markets to US competition and protecting foreign companies' intellectual property.

On Wednesday, US Trade Representative Robert Lighthizer slammed Beijing for failing to offer "meaningful reform" on aggressive trade policies, and threatened tariffs on Chinese autos.

But how far can Xi go in overhauling the model that has powered China to second place in the world economic rankings? He did vow on Wednesday that China would boost protection of intellectual property. But foreign firms in China complain that such promises are all too routine and ring hollow.

At best, analysts say, there will be a temporary truce at the G20 to give both Trump and Xi something to crow about.

French President Emmanuel Macron warned against the risk of "a tete-a-tete between China and the United States and of a destructive trade war for all" ahead of the summit, in an interview with Argentine daily La Nacion.

"If we do not show concrete progress, our international meetings become useless and even counterproductive," he said.

Despite doubts that a separate planned encounter at the G20 between Trump and Russian President Vladimir Putin would go ahead, Kremlin spokesman Dmitry Peskov told journalists Thursday that Washington had "confirmed the meeting."