U.S. President Donald Trump predicted Sunday that China would lower its trade barriers, expressing optimism despite escalating trade tensions between the world's two largest economies that have roiled global markets in the past week.

The two countries have threatened each other with tens of billions of dollars' worth of tariffs in recent days.

Chinese officials have said this is not the time for negotiations. But Trump administration officials have stressed that the tariffs are not yet in place and that the dispute could be resolved through talks.