Neither Biden nor Xi made public mention of the clash over disputed territory that has pitted China against the United States and its Asian allies.
An editorial in the state media China Daily charged, however, that Washington "is turning a blind eye to Tokyo's provocations," calling that the "root cause of the tensions." It said that "the United States is wrongly pointing an accusing finger at China for 'unilaterally' changing the 'status quo' in the East China Sea."
Biden told reporters after his initial talks with Xi that the relationship between the two major powers will significantly affect the course of the 21st century. If the U.S. and China can get that relationship right, the possibilities are limitless, he said to reporters who were allowed in briefly after the vice president met with Xi.
Biden said he came to Beijing because complex relationships require sustained engagement at high levels. He said Xi's candor and constructive approach had left an impression on him.
"Candor generates trust," Biden said. "Trust is the basis on which real change—constructive change—is made."
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The two leaders had a second meeting involving larger delegations and a working dinner planned for later Wednesday.
Absent from Biden's public comments was any discussion of U.S. concerns over China's new air defense zone. Only a day earlier, Biden pledged to raise those concerns "with great specificity" with Xi and other Chinese leaders, adding that China's move was deeply concerning.
"This action has raised regional tensions and increased the risk of accidents and miscalculation," Biden said in Tokyo Tuesday after meeting with Japanese President Shinzo Abe.
Japan has been on edge for the past two weeks since China unilaterally declared any planes flying through the zone must file flight plans with Beijing. The airspace sits above tiny islands that are at the center of a long-running territorial dispute between China and Japan.
The U.S. refuses to recognize the zone, but Biden has avoided calling publicly for Beijing to retract it, wary of making demands that China is likely to snub. Rather, the vice president hoped to persuade China not to enforce the zone or establish similar zones over other disputed territories.
After meeting with Biden, Xi said the U.S.-China relationship had gotten off to a good start this year "and has generally maintained a momentum of positive development." But he said the global situation is changing, with more pronounced challenges and regional hotspots that keep cropping up.
(Read more: Biden urges Japan, China to lower tensions)