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US President Donald Trump faces his biggest test as a world leader when he meets Chinese leader Xi Jinping for the first time in Florida.
Mr Trump has already signalled it will be difficult and warned he will go it alone on North Korea if China doesn't help.
But trade is likely to dominate. Mr Trump has staked his presidency on bringing jobs back to the US and reducing America's huge trade deficit with China.
Many experts say his plans are unlikely to succeed.
What happens when the two leaders meet at Mr Trump's Mar-a-Lago resort in Florida on Thursday (local time) will be felt around the world.
Together China and America make up 40 per cent of the global economy.
Presidents' traditional trade stance reversal
James McGregor has been living in China for more than 25 years and is a former head of the American Chamber of Commerce in China.
"The Chinese will want to take measure of Donald Trump and figure out how they can deal with him," he said.
"There is two strong personalities running each country so it's going to be person to person.
"The 19th party congress is coming up for Xi Jinping later this year so he will want to look all knowing and powerful … The Chinese don't want anything embarrassing to happen so they want a quick talk and get out of town."
On the face of it Mr Trump and Mr Xi are totally different people: Mr Trump the dealmaker, real estate developer, reality-TV-star-come-president, and Mr Xi the hard-line communist party supremo.
The great irony is their public stances have been reversed.
Mr Xi is now spruiking himself as a champion of free trade, sounding like US presidents of the past.
Mr Trump on the other hand is going back to the era of protectionism and idea that it will lead to greater prosperity and strength.
Trade imbalance a focus for Trump
A basis of co-operation needs to be found for there is a lot at stake. Annual trade between the US and China is now about $US600 billion.
America's biggest exports are aircraft, machinery and soybeans, totalling $US116 billion.
But Chinese exports, at $US463 billion, are four times bigger — the major ones being consumer electronics, clothing and machinery.
Mr Trump wants this huge trade imbalance addressed when he meets Mr Xi.
Mr McGregor says Mr Trump's team will be pushing "countervailing duties, anti-dumping measures, all steel aluminium dumping, and excess capacity being dumped overseas".
"The US is going to focus on that and that's people he had brought into his administration," he said.
China can quickly retaliate to hurt vulnerable US, Trump
But most economists say Mr Trump's pledge to bring back jobs to the rust belt of America is unrealistic.
To remain competitive, US workers would have to accept much lower wages and worse conditions.
Professor Michael Pettis from Peking University says it's just not that simple anymore.
"In the manufacturing of most electronics there is often one leg of that's gone through China because it has cheap disciplined labour and cheap domestic costs," he said.
"When the US buys a finished product it could have gone through five to 10 different countries. So it's very complex these days."
Mr Trump's threat to impose tariffs of up to 45 per cent on Chinese imports will also hit US firms, such as Apple, which assemble goods in China.
American consumers will lose out with much higher prices.
Mr McGregor says if any kind of trade war erupts, China can easily and quickly retaliate to hurt Mr Trump.
"They are going to be screaming at the White House and it's going to be farmers and workers, his base — people that voted for him — that would get hit by this," Mr McGregor said.
"He's going to wake up pretty quickly. China will go after big multinationals like Walmart, GE, Caterpillar, Intel — they have big stakes in China.
"If it comes to that everyone will lose."
'The President has been schooled'
China has been one of the biggest benefactors of globalisation so it will continue to push its win-win message.
It says America has benefited, and in 2015 bilateral trade and investment created 2.6 million American jobs and saved every American family $US850 a year.
Henry Wang, from the Chinese Think Tank Centre for China and Globalisation, says Mr Xi may offer Mr Trump job-creating Chinese investment in America and greater access to Chinese markets.
Mr Xi at least will want to hear Mr Trump is committed to the one China policy.
Mr Trump is a businessman, so if he is looking for the best deal, the biggest benefits, who else can be the best provider but China?
At end of the day Mr McGregor too, says Mr Trump is likely to be pragmatic.
Mr McGregor and many others have been to Washington to advise the new administration.
"The President has been schooled," he said.
"All these CEOs going into the White House who have big stakes in China are telling him if you try to do China like Mexico, you're going to have a bad day.
"So he's backed off until recently. Now he's ramping up, but I don't think he will be wacko. I think he'll be forceful, but not really wacko."
Topics: trade, donald-trump, world-politics, government-and-politics, united-states, china, asia
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