Beijing(CNN) Chinese leader Xi Jinping has taken a veiled swipe at US President Donald Trump the day before the US midterm elections, denouncing a "winner-takes-all" attitude to international trade.

Xi made the remarks during a speech Monday at the opening of the inaugural China International Import Expo in Shanghai, an event designed to demonstrate the country's importance as a destination for foreign goods.

Despite the prominence of the event for China, no senior US government officials attended, further underscoring the strained relationship between the two countries.

Although he never mentioned Trump or the United States by name during his speech, Xi said there was no room for protectionism in international trade.

"Today, with the deepening of economic globalization, 'law of the jungle' and 'winner-takes-all' are a dead end," he said.

"A global economy is an irreversible trend and won't change because of one person," the Chinese leader told delegates. "Every country should fight against protectionism and build an open economy."

A security guard stands at the entrance to the first China International Import Expo (CIIE) in Shanghai on November 5.

Xi's presence was intended to show the importance Beijing is placing on the trade fair, which was attended by more than 3,600 companies from over 150 countries, according to state-run broadcaster CGTN.

Xi and Trump are expected to meet one-on-one at a G20 summit in Argentina in late November to address the trade tensions. The two leaders spoke for the first time in months on Thursday in a phone call that Trump described as "long and very good."

The call raised hopes among investors that the two governments could be moving toward a ceasefire in the trade war after months of escalation.

But there remain many unanswered questions about how Beijing can appease US complaints over unfair trade practices and technology theft, which other major economies like the European Union have also raised.

Speaking to CNBC on Friday, top White House economic adviser Larry Kudlow said the two countries were "not on the cusp of a deal."

During his speech, Xi promised to open the Chinese economy further to international investment, as well as protecting foreign businesses already in operating in the country.

"China will remain a strong advocate of openness at the global level, and will continue to act as a stable engine of global growth, a big market with enormous opportunities, and an active supporter of global governance reform," he said.

While China has gradually opened parts of its economy to foreign companies over the years, governments and industry groups from other countries have repeatedly complained about the slow pace of change as well as other difficulties, such as unequal treatment by regulators.

Xi's comments came during the final stretch of the campaign for the US midterm elections, in which Trump's Republican Party could lose control of the House of Representatives to the Democrats.

Experts say China shouldn't expect a significant change in trade policy if the Democrats do make inroads in Congress, where the Republicans currently control both the House and the Senate.

"I don't think Beijing understands just how popular in DC a tougher line on China is," Isaac Stone Fish, senior fellow at the Asia Society, told CNN.