The United States wants South Korea and Japan to exercise restraint in handling their historical and territorial disagreements, a senior State Department official said Thursday.

“I have to say that the recent spate of tensions between Japan and Korea have caused concerns,” the official told reporters on the condition of anonymity.

“We are, again, urging restraint, calm, and statesmanship in terms of dealing with these issues.”

Washington‘s key Asian allies _ Seoul and Tokyo _ have been at loggerheads for weeks over Dokdo, a pair of largely uninhabited outcroppings in the East Sea.

Dokdo are effectively controlled by South Korea.

But Japan, which colonized Korea from 1910-45, claims them and is seeking to file a petition with the International Court of Justice.

Seoul says that its ownership of Dokdo, both legally and historically, is not disputable.

Tensions between the neighboring nations have soared, especially in the wake of South Korean President Lee Myung-bak’s recent visit to Dokdo.

Lee has also demanded that Japan offer a sincere apology for its wartime atrocities.

The Seoul-Tokyo stand-offs have apparently taken a toll on Washington‘s push for stronger trilateral cooperation.

The U.S. government normally maintains a wait-and-see attitude about tensions between the two sides, and in the past has reiterated its hopes for them to resolve their bilateral issues peacefully.

The senior State Department official, however, indicated Washington now will try to arbitrate between the allies.

“I think we would encourage a variety of steps, unofficial dialogues, people-to-people engagements, business endeavors to stand up and speak out on the importance of Japan and South Korea working together as partners in the 21st century,” the official said. “And that’s something that we’re going to be exploring further in our bilateral interactions with both countries in the coming weeks.”

Secretary of State Hillary Clinton is heading to Asia later this week for trips to the Cook Islands, Indonesia, China, Timor-Leste, Brunei.

She will also attend an Asia-Pacific Economic Cooperation (APEC) summit to be held in Russia from Sept. 8-9, in which both South Korean and Japanese leaders will participate. (Yonhap News)