U-S President Donald Trump said last week that the study would be completed in three to four weeks.
A European diplomat said: "China wants the European Union to stand with Beijing against Washington, to take sides".
"We put a halt on all investment, not just because we will be losing money, but because we don't know if growing in the USA is the right move if we won't be an exporting country", Ken Maschhoff, co-owner of the country's largest family-owned pork producer, told CNBC.
"China will not bow down in the face of threats and blackmail and will not falter from its determination to defend free trade and the multilateral system".
It now runs a large trade deficit with China, its biggest trading partner. "As long as the United States issues a so-called tariff list, China will take necessary measures to firmly protect its legitimate interests", Chinese Foreign Ministry spokesman Lu Kang said at a daily news briefing. Economists have warned that the tariffs will damage economic growth and cost jobs, and could escalate into a full-blow trade war between the world's two largest economies. Japan's government has warned in a report that a higher USA tariff on auto imports could backfire, jeopardizing hundreds of thousands of American jobs created by Japanese auto-related companies, raising prices for US consumers and devastating the US and global economy.
Still, China's stance is striking given Washington's deep economic and security ties with European nations.
China lashed out at the US Thursday, the day before a trade war is set to erupt between the world's top two economies, saying that Washington is effectively "firing at itself".
China has issued a safety warning to its citizens travelling to the United States amid rising tensions between the sides over accusations of unfair trading practices and other disputes.
"Trump has split the West, and China is seeking to capitalize on that". China's list is created to inflict pain on USA farmers and other groups that are important to President Donald Trump's political base.
A report by New York-based Rhodium Group, a research consultancy, in April showed that Chinese restrictions on foreign investment are higher in every single sector save real estate, compared to the European Union, while numerous big Chinese takeovers in the bloc would not have been possible for EU companies in China. But EU officials expect any moves to be more symbolic than substantive.
Added to the tariffs are the increased scrutiny on Chinese investments in the United States, which the government says are sensitive for economic or national security reasons, which already has reduced incoming investment.