China has accused the US of unleashing the "largest-scale trade war" as the global giants slapped tit-for-tat duties on $34bn (£25.6bn) worth of each other's imports.
Ramping up the criticism in the escalating dispute, Beijing said Donald Trump's administration was "behaving like a gang of hoodlums" after Washington pressed ahead with levying 25% tariffs on a range of products - and retaliated in kind.
Goods affected include Chinese machinery, electronics and cars.
The US president has also threatened to raise the stakes, warning the US could eventually target more than $500bn (£378bn) worth of Chinese goods.
Chinese Premier Li Keqiang has warned a trade war "is never a solution".
He said: "China would never start a trade war but if any party resorts to an increase of tariffs then China will take measures in response to protect development interests."
It has been reported that some Chinese ports had delayed clearing cargoes from the US, as customs officials waited for guidance on imposing increased tariffs.
Ford has already said it will not yet hike prices of imported models in China.
An analysis of dozens of imported US products facing higher duties such as pet food, mixed nuts and whiskey showed prices were little changed on Friday.
"It will take three, six or 12 months before their impact becomes visible," Tokyo branch manager for State Street Bank and Trust, Bart Wakabayashi, said.
Economists say the tariffs signal the start of the long-expected trade war. While the current level of duties will only have a marginal effect, if they were to escalate it would have a major impact for both nations as well as acting as a brake on the global economy.
European Union Trade Commissioner Cecilia Malmstrom raised her concerns in a post on Twitter, warning: "Clearly damaging for the world economy. Trade wars are bad and not easy to win."
Mr Trump imposed the levies over what he claimed was intellectual property theft by Beijing and barriers to entry for US businesses, as well as a $375bn (£283bn) US trade deficit with China.
In response, the state-run China Daily newspaper said: "In effect, the Trump administration is behaving like a gang of hoodlums with its shakedown of other countries, particularly China.
"Its unruliness looks set to have a profoundly damaging impact on the global economic landscape in the coming decades, unless countries stand together to oppose it."
China's tariffs on hundreds of US goods include top exports such as soya beans and cotton, hitting farmers in states that backed Trump in the 2016 election, such as Texas and Iowa.
Official US figures later showed the the US trade deficit with the rest of the world hit an 18-month low in June because of record exports though the dollar was hit when employment figures showed the jobless rate rising to 4%.
Stock markets, which have wobbled in recent weeks as the fears of a US-inspired global trade war have intensified, were fairly calm on Friday as the tariff developments had been anticipated earlier in the week.
Just a few weeks ago, Mr Trump brought in a 25% tariff on steel and a 10% tariff on aluminium from the EU, Canada and Mexico, citing national security interests
The EU responded with tariffs of its own.
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