The U.S. says that its tariffs on steel and aluminum are fair but that the other countries' were not.
Later, President Xi Jinping met the European leaders and said the two sides should "join hands to defend multilateralism and a rules-based free trade system", Chinese state television said.
"This is why I am calling on our Chinese hosts, but also on presidents Trump and Putin, to jointly start this process from a thorough reform of the WTO (World Trade Organisation)", Mr Tusk said.
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 a year ago - to combat what the U.S says are Beijing's trade abuses.
Trump's steel and aluminum tariffs broke that taboo.
The data came after the administration of US President Donald Trump raised the stakes in its trade row with China on Tuesday, saying it would slap 10 percent tariffs on an extra $200 billion worth of Chinese imports, including numerous consumer items.
European council President Donald Tusk delivers a speech during a joint press conference on the second day of a summit of European Union (EU) leaders on March 23 2018, in Brussels.
If the USA goes ahead with tariffs on $250 billion, the hit to China's growth could mean a drag of 0.3 percentage point, according to Morgan Stanley.
Long accused of protectionist tactics that make it a hard place for foreign firms, China is trying to reverse that narrative amid the escalating trade war by approving huge investments, such as a $10-billion petrochemicals project by Germany's BASF.
The World Trade Organisation should be reformed rather then destroyed, he said, adding, "There is still time to prevent conflict and chaos". Among the progress hailed was an exchange of offers aimed at moving toward a bilateral investment treaty, the establishment of a "China-EU co-investment fund" and a plan to enforce intellectual property rights.
The gross domestic product figures were in line with market expectations, but the new data also showed slower-than-expected growth in China's industrial output, pointing to slowing momentum and prompting some analysts to call for stronger government measures to support growth. But Chinese officials have tried to appeal to American companies as allies.
"The EU and China are entering into new territory as ad hoc coalition partners", Fraser Cameron, the director of the EU-Asia Centre, told EUobserver.
Apart from trade and market access, the two sides have recently clashed over the Eurasian connectivity vision of China's massive Belt and Road Initiative (BRI), an ambitious $1 trillion infrastructure project that aims to bolster China's trade and investment links with economies in Asia, Africa and Europe.
European Union foreign policy chief Federica Mogherini repeated remarks that a change in United States administration does not mean a change in friendship, adding Europe will always "be close friends and partners" with Washington.
In a sign Beijing is seeking alternative supplies of the commodities as it hit USA imports with extra tariffs, China had dropped import tariffs on a range of animal feed ingredients from several Asian countries.
The Center for China in the World Economy hinted that China could strike back by sanctioning Apple. -China dispute could go beyond trade.
"The European Chamber is looking forward to seeing a well-negotiated agreement that addresses market concerns in all sectors and creates a more transparent and stable regulatory business environment", said Harborn.