DA NANG, Vietnam—China’s President Xi Jinping called for a more inclusive global economy to gird for technological change, staking a claim to free-trade leadership in his first address to a major multilateral forum since consolidating executive power at home last month.

Speaking at the Asia-Pacific Economic Cooperation’s CEO Summit, a forum of business leaders from 21 economies, Mr. Xi laid out a message that differed starkly from the “America First” approach that U.S. President Donald Trump offered moments earlier at the same forum.

“Should we steer economic globalization or dither and stall in the face of challenges?” Mr. Xi said. “Here’s my answer: We must advance with the trend of the times and live up to our responsibility.”

Friday’s address underscored a shift in Mr. Xi’s public tone on multilateral trade policy. In his first address to the gathering in 2013, his speech was focused on assurances of China’s commitments to opening up and to change. In subsequent years, Mr. Xi called for “connectivity” and sustainable development, and more recently he inveighed against U.S.-led efforts to build the Trans-Pacific Partnership, a multilateral trade pact that excluded China.

But on Friday, he recast China’s role as a newly minted guardian of globalization.