The S&P/TSX composite index gained 131 points early, but then closed down 166.51 points or more than one per cent to 14,721.75. The Dow Jones Industrial Average ended down 1 percent, while the Nasdaq fell 1.6 percent, also on weakness in technology and internet shares.
"It looks as if rivalry and confrontation became the prevailing aspect of our path ahead", said Cui, speaking during a trade war in which both countries have slapped punitive tariffs on hundreds of billions of dollars worth of imports.
Over the past year, said Cui, "we have heard enough of trade war threats, assertions about strategic rivalry, sabre rattling in the South China Sea, and even unfounded accusations against Chinese students and scholars".
That prospect now seems highly unlikely.
In a speech that made no direct mention of Trump or his government, Cui expressed confidence in the capacity of people-to-people friendship, rather than political wrestling, to carry the US-China relationship forward. "And if they don't give us any information, it's just hard to see how that becomes fruitful". "The volume of the Chinese-US trade depends on the US side", he pointed out. That took place in 1999 during negotiations for China's entry into the World Trade Organisation.
The experience has been repeated this year.
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Though disappointment came in a Champions League quarter-final defeat to Liverpool and FA Cup fifth-round exit at the hands of League One side Wigan Athletic.
Trump said on Friday that "because of our much tougher trading stance with China, I do not believe they are helping with the process of denuclearisation as they once were", despite United Nations sanctions against the nuclear-armed regime. However, Trump overturned the deal a few days later on the grounds that it was not sufficient. IBM Chairman and CEO Ginni Rometty said the deal will make IBM the world's biggest hybrid cloud provider, meaning it will offer companies a mix of on-site, private and third-party public cloud services.Red Hat soared 45.4 percent to $169.63, reversing its losses from earlier this year. "You can not have some tentative agreement one day and reject it the next".
Another White House spokeswoman said there was "nothing new at this time" regarding tariffs on Chinese goods.
The conflict goes far beyond negotiating tactics, however. The effects could be especially severe for technology companies, which make many of their products in China, and for industrials. So China probably has good reason to feel wary.
This is a demand that the Chinese regime can not meet. But there are risks in the background, from the American midterm elections to trade talks with China.
But far more is involved.
The energy sector closed off more than three cent as the price of crude oil continued to fall as investors remained concerned about slowing global demand led by weakness in China.
Having completely abandoned any claim to promote social equality, let alone bring about an advance to socialism, the Chinese regime is widely regarded as representing an ultra-wealthy capitalist oligarchy.