U.S. President Donald Trump has warned he may ultimately impose tariffs on more than $500 billion worth of Chinese goods - almost the total amount of U.S. imports from China previous year - to combat what the U.S says are Beijing's trade abuses.
Washington added 25 per cent tariffs on $34 billion of Chinese goods on July 6 in response to complaints Beijing steals or pressures companies to hand over technology.
China and the EU together account for about one third of the global economy, yet European foreign direct investment into China has reached a cap, said EU Commission President Jean-Claude Juncker, alluding to persistent complaints about reciprocal market access. "Instead of working with us to address a common problem, some of our trading partners have elected to respond with retaliatory tariffs created to punish American workers, farmers and companies", U.S. Trade Representative Robert Lighthizer said in an emailed statement.
Mr Tusk urged the US, China and Russian Federation to work with the European Union to ease global trade tensions, saying that the worldwide order needed responsible reform.
China has tried to solicit support from Europe, South Korea and other governments in resisting Trump's trade policies, according to the AP. The 28-country European trade bloc responded with import taxes on $3.25 billion of US goods.
The US move is the latest salvo in a growing trade war started by the imposition of US tariffs on steel and aluminium imports.
Shipping containers are seen at the port in Shanghai, China. European leaders have criticized Trump's tactics but share United States criticism of China's industrial policy and market barriers.
Chinese Premier Li Keqiang said Monday that China and the European Union had agreed to take steps to "safeguard free trade" and the global multilateral regulatory system.
A recent report from the European Union, cited by the Associated Press, said Beijing erected more import and investment barriers than any other nation a year ago, making it harder for electronics and cybersecurity companies to do business here.
Citing its investigation that began in August 2017, the Trade Representative's tariff notice said it concluded that China's actions and policies "are unreasonable or discriminatory and burden or restrict USA commerce".
The EU cited rising obstacles in China's semiconductor, cybersecurity and other industries.
Mr Juncker said that China, often criticised for protectionist attitudes towards foreign companies, could help matters by being more open. When a BMW executive said joint a German-Chinese agreement this month to co-operate in developing intelligent vehicles would benefit from the early release of standards by Beijing for the technology, Li asked whether he was concerned joint formulation of those standards would undermine his company's intellectual property.
The EU and China have agreed to develop the EU-China strategic partnership at the 20th summit, which comes just hours after President Trump labelled both a "foe".