HANGZHOU, China — Chinese President Xi Jinping called Sunday for leaders of the United States, Germany and other major economies to resist pressure to raise trade barriers as they opened a summit amid sluggish global growth and disputes over China’s steel exports and Apple’s Irish tax bill.

China made trade a theme of the Group of 20 meeting even as Beijing faces complaints it is flooding world markets with low-cost steel, fueling demands for trade curbs. The president of the European Commission highlighted the conflict by calling for the summit to take action.

Opening the two-day meeting in this lakeside city southwest of Shanghai, Xi called for more innovation to spur economic growth and reforms to global financial and economic management. He appealed for cooperation in taxes, anti-corruption and measures to “improve the ability of the world economy to resist risks.”

Chinese officials said earlier that Beijing would propose a plan to boost trade and innovation through regulatory changes and closer government cooperation.

“We should build an open world economy,” Xi said before an audience that included President Obama, German Chancellor Angela Merkel, British Prime Minister Theresa May and leaders from Japan, South Korea, India and other governments.

Also Sunday, the head of the European Union’s governing body called for action on China’s bloated steel industry.

The G-20 meeting “must urgently find a solution” to excess steel production, said Jean-Claude Juncker, president of the European Commission. He called on Beijing to accept a monitoring mechanism for overproduction that Beijing’s trading partners blame for low prices and job losses.

Juncker also rejected U.S. criticism of the order for Ireland to collect $14.5 billion in back taxes from Apple.

“Free trade must be fair trade,” Juncker said at a news conference with Donald Tusk, president of the European Council.