But if the Trump administration pursues an additional $100 billion in tariff, the new $150 billion total would exceed the roughly $130 billion in goods China imports from the U.S. That would force Beijing to seek other options.

Last year, the United States sold $12.4 billion in soybeans to China - almost 60 percent of all USA soybean exports.

The effective date will depend on when the U.S. action takes effect. The U.S says China treats American companies unfairly by restricting access to its markets and stealing proprietary technology.

"This is what a trade war looks like, and what we have warned against from the start", Matthew Shay, National Retail Federation President and CEO, told Reuters.

"U.S. companies at this point would like to see robust communication between the United States government and the Chinese government and serious negotiation on both sides, hopefully to avoid a trade war", said the chairman of the American Chamber of Commerce in China, William Zarit.

Shanghai crude futures trading will resume on Monday after public holidays in China.

In March, Trump began the process of imposing tariffs against steel and aluminum imports, alleging that a range of countries were flooding the US with cheap metals in a way that harmed USA workers. That development follows Trump's earlier pitch for $50 billion in tariffs on Chinese products.

The further tariffs are being considered "in light of China's unfair retaliation", according to a White House statement.

Analysts at Oxford Economics, referring to the fact that the tariffs are not yet in effect, said in a note to clients that, "Importantly, these threatened tariffs will be subject to negotiation, and therefore shouldn't be considered as final".

"What China needs to do now is to make the United States pay the same price" so Americans "understand anew the Chinese-U.S. strength relationship", the newspaper said.

The duelling trade threats rattled Wall Street on Friday, ending a volatile week with major indexes closing down more than 2 per cent on the day.

President Donald Trump upped the ante late Thursday with a threat to slap tariffs on a further $100 billion of Chinese exports.

Beijing announced its list of 106 American products that will be hit with 25% tariffs on Wednesday.

Other than steel and aluminum, the tariffs are only threat at this point: the USA will have a 30-day comment period before determining the final list of Chinese goods on the hit list, and China also is holding off pending talks. We covered the original tariff announcement here.

"The problem is the method", a European official told AFP, when asked about Trump's hardball approach to Beijing.

President Donald Trump, wanting to protect US farmers from China's threatened tariffs, may end up pitting his country against many more nations in a trade spat that has hit global markets and anxious the worldwide business community, experts said Friday.

The White House said Trump had instructed the Office of the United States Trade Representative, the agency responsible for developing and recommending trade policy, to consider whether the additional tariffs would be appropriate under section 301 and, if so, to identify which products they should apply to.

He said he had also instructed agricultural officials to implement a plan to protect USA farmers and agricultural interests.

What could the impact be?

Trump's latest tariff threat was met with criticism from members of his own Republican party. "If American consumers have to spend more on Chinese imports, they have less to spend on everything else". "We are on a unsafe downward spiral and American families will be on the losing end". "Let's absolutely take on Chinese bad behavior, but with a plan that punishes them instead of us". Farm states generally backed Trump in the 2016 election and their exports could be hurt. Soybean prices fell to their lowest level in two years on Wednesday after China's list came out, Bloomberg reported.

Benchmark U.S. crude dropped $1.17, or 1.8 percent, to $62.37 a barrel in NY while Brent crude, used to price worldwide oils, lost 92 cents, or 1.3 percent, to $67.41 per barrel in London. Those animals are in turn used to help feed China's enormous population.

"We regret that soybeans are on the list".

"These are some of the companies most exposed to potential tariffs".

China is the largest market for USA soy and the threat of tariffs on exports of the commodity has the potential to whip up trade anxieties in stalwart Republican areas.