Relief has swept across world financial markets after US President Donald Trump pushed back a March 2 deadline in a trade dispute with China.
But the respite might not last.
A look at the dispute:
What are the US and China fighting about?
The United States accuses China of deploying predatory tactics in a headlong push to challenge American technological dominance. These, the US says, include: outright theft of trade secrets, forcing foreign companies to hand over technology as the price of access to the Chinese market, and unfairly subsidising Chinese tech companies and using regulations to hobble their foreign competitors.
The accusations elevate the standoff from a typical trade dispute to a battle over whether the United States or China dominates the industries of the future, the outcome of which has implications for national security.
Trump is also obsessed with America's massive trade deficit with China, $US336 billion ($A468 billion) in 2017 and likely higher last year.
Critics complain that the administration has been inconsistent about what it wants - sometimes demanding sweeping changes in Chinese economic policy, sometimes seeming willing to settle for China just buying more American stuff to narrow the trade deficit.
Robert Daly, director of the Kissinger Institute on China and the United States at the Wilson Center think tank, said he would be disappointed if the Trump administration settles only for more exports to China and vague promises to make structural reforms. "The Trump administration could have had that in week one," Daly said.
What's happened so far?
In July, the Trump administration gradually began slapping import taxes on Chinese goods to pressure Beijing into changing its policies. It now has imposed 10 per cent tariffs on $US200 billion ($A279 billion) in Chinese imports and 25 per cent tariffs on another $US50 billion ($A70 billion).
Twice, Trump has pushed back plans to raise the tariffs on the $US200 billion ($A279 billion) to 25 per cent. He extended a January 1 deadline by three months after meeting Chinese President Xi Jinping in Buenos Aires December 1. And on Sunday, following meetings last week between US and Chinese negotiators, he delayed indefinitely the tariff hike that was scheduled to kick on March 2.
The US is also restricting Chinese investment in high-tech American industries and US exports of sensitive technology to China.
Meanwhile, the Chinese have punched back by slapping import taxes on $US110 billion ($A153 billion) in US goods, focusing on soybeans and agricultural products in a direct shot at Trump supporters in the American farm belt.
Forecasters at the World Bank, the International Monetary Fund and the Organisation for Economic Cooperation and Development have all downgraded their forecasts for the global economy, citing the heightened trade tensions.
Are US and Chinese negotiators making headway?
They say they are but haven't provided many particulars. Trump tweeted on Sunday that negotiators had made "substantial progress" on issues including protection of intellectual property, coerced tech transfer, currency manipulation and US access to the Chinese farm and services markets among "many other issues." China's official Xinhua news agency echoed that assessment.
Trump has said he would likely have to meet one-on-one with Chinese President Xi - probably late next month at Trump's Mar-a-Lago resort in Florida - to resolve the thorniest issues.
What happens next?
Trump sees the stock market as a measure of the success of his economic policies. Investors' view is clear: When US-China negotiations go well, American stocks rise. When talks falter, they drop.
So the question is whether Trump, having taken US-China economic relations to the brink, has the patience to hold out in the face of likely stock-market volatility for an enforceable deal that requires China to change its behaviour. Or whether he'll agree to more exports and promises of change.
"If the US has already achieved quite a bit, and we are just clarifying the details of substantial Chinese concessions, then that's not a huge concern," said Scott Kennedy, a China expert at the Center for Strategic and International Studies. "But if the US has come away with very little in terms of binding commitments (after dropping the tariff deadline), then the chance of getting more in the coming weeks could be quite low."
Daly at the Wilson Center faulted the administration for not imposing a new deadline. "They are expert at the use of time and delay until conditions have changed and leverage has been lost, to get a better outcome," Daly said.
Trump has also alarmed Canada and critics by suggesting the US might drop criminal charges against Chinese telecommunications giant Huawei and its chief financial officer, Meng Wanzhou, in a quest to cut a deal. The US has charged Huawei with lying about violating sanctions against Iran and with stealing trade secrets. Canada arrested Meng December 1 at America's request and is weighing whether to extradite her to the United States. China arrested two Canadians in apparent retaliation.
Former Canadian Ambassador to China David Mulroney tweeted on Monday that "it's now the US that has to hang tough, and not sell out its integrity in Huawei case for a trade deal with China)."
