Putin, meanwhile, said "the time has come to have a thorough discussion on various global problems and sensitive issues".
European Council president Donald Tusk was speaking in Beijing at the opening of a summit between China and the European Union, just hours ahead of a summit between Mr Trump and Mr Putin in Helsinki. Articles appear on euronews.com for a limited time.
At the business event, Li invited executives from European companies operating in China to share their problems.
The yuan, meanwhile, has been sliding, though a weaker currency might help exporters facing the USA tariffs.
China's trade surplus with the USA swelled to a record in June as its overall exports grew at a solid pace, a result that could further inflame a bitter trade dispute with Washington. When a BMW executive said joint a German-Chinese agreement this month to cooperate 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 U.S., however, took a fresh step Monday in an escalating trade dispute by launching separate disputes at the WTO against Canada - as well as the European Union, China, Mexico and Turkey - over each jurisdiction's set of countermeasures on American imports.
However, it might help Beijing rally support from governments which have criticised Mr Trump for going outside the WTO to impose tariffs on Chinese and other imports.
"So this makes the Powell speech important this week, if he makes any comments on how the trade tariffs may affect the U.S. economy", he said, referring to U.S. Federal Reserve chair Jerome Powell's scheduled testimony to lawmakers on Tuesday.
Officials have expressed hopes of producing a modest communique that will affirm both sides' commitments to the multilateral trading system.
Barack Obama returns to Kenyan 'home'
The writer, Mr Andrew Maina, said he launched the book during Obama's visit to ensure the message of cohesion reaches many people. He walked out when Obama was just two and died in a auto crash in Nairobi in 1982, aged 46.
Beijing and Brussels are in the process of negotiating a bilateral investment treaty, which is meant to provide more legal protection and market access for investors on both sides.
China retaliated, saying the U.S. had launched the "largest trade war in economic history".
"Thanks to the new economy, China managed to sustain a stronger growth momentum", said Raymond Yeung, chief greater-China economist for Australia & New Zealand Banking Group Ltd.in Hong Kong.
China's ambassador to the EU on Sunday wrote in Chinese state media that the focus of the annual China-EU leaders meeting would be on how the two sides could become a "standard of stability" amid the "din of unilateralism and protectionism".
On March 8, Trump concurred with the Secretary of Commerce's finding and imposed tariffs on imports of steel and aluminum.
Meanwhile, the USA and China have in recent weeks exchanged escalating tariffs.
For the two sides, however, the most important thing - on the day when USA and Russian presidents, Donald Trump and Vladimir Putin, were meeting in Helsinki - was to give a signal that the two main economic powers next to the U.S. could work together to uphold multilateralism in an uncertain global environment.
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