Danny Russel, the assistant secretary of state for East Asia, said he held "candid" talks on growing tensions during recent stops in Beijing, Seoul and Tokyo.
"There are multiple perspectives, but one thing is certain -- none of the problems, none of these tensions, can be solved by any one party alone," Russel told reporters.
"Frankly, we look to each of our friends and partners in the Asia-Pacific region to make a contribution to good relations and to good neighborliness," he said.
Russel said that Japan and South Korea, both US allies and democracies, had shared values that should "serve as the foundation for long-term trust." He said that China and Japan, as Asia's two largest economies, "can and must work together" in the interests of their citizens.
In the latest row tied to historical disputes, Japan instructed education chiefs to teach children that islands contested with South Korea and China unequivocally belong to Tokyo. South Korea immediately protested.
In December, Japanese Prime Minister Shinzo Abe, known for his nationalist views, paid a pilgrimage to the Yasukuni shrine which honors war dead including convicted war criminals. South Korea and China voiced anger at the shrine visit, which also prompted rare US criticism of Japan's leadership.
Tensions soared in the region in November when China declared an Air Defense Identification Zone over a vast part of the East China Sea, requiring pilots to report to Beijing when flying over islands administered by Japan.
Russel reiterated US warnings to China not to create a similar zone in the South China Sea, where Beijing has disputes with the Philippines, Vietnam and other countries.
"We have made clear that we urge China not to attempt to implement the ADIZ and certainly not to replicate it in other sensitive areas, including and particularly in the South China Sea," he said.
After China's move, the United States, Japan and South Korea all defied Beijing by flying military planes through its declared zone.