United States Defense Secretary Chuck Hagel said Saturday he will convey to Japanese leaders that the U.S. is strongly committed to protecting their country's security, Reuters reported.
China, Japan and others are in bitter territorial disputes, including over disputed islands in the East China Sea, according to Reuters.
"It's a pretty predictable, I think, reaction, not just of nations of this area and this region but all over the world," Hagel told Reuters. "I think anytime you have a nation - Russia in this case - try to impose its will to refine and define international boundaries and violate the territorial integrity and sovereignty of a nation by force, all of the world takes note of that."
Assistant U.S. Secretary of State Daniel Russel also said this past week that Russia's annexation of Crimea heightened concern, particularly among some Southeast Asian nations, about the possibility of China "threatening force or other forms of coercion to advance their territorial interest," according to Reuters,.
The U.S. has said it takes no side on the question of the disputed islands' sovereignty, but it recognizes Japan's administration of them and has responsibilities to protect Japanese territory under a mutual defense treaty, Reuters reported.
Hagel said the U.S. wants the countries in the region to resolve the disputes peacefully. But he added that the United States would honor its treaty commitments, according to Reuters.
Hagel's trip to Japan comes at the close of a three-day meeting in Hawaii with defense ministers from Southeast Asian nations, Reuters reported. He will later travel to China, where he said he looks forward to talks about expanding military cooperation as well as the chance to air differences on the disputes.
Hagel said he would encourage Chinese leaders to abide by the international code of conduct, according to Reuters.
China has expressed displeasure about recent moves by the U.S. to provide additional military assets and support to Japan, Reuters reported.
Last October, the U.S. and Japan agreed to broad plans to expand their defense alliance, including plans to position a second early warning radar there by the end of this year, according to Reuters. There is one in northern Japan and the second one would be designed to provide better missile defense coverage in the event of a North Korean attack.
The U.S. will begin sending long-range Global Hawk surveillance drones to Japan this month for rotational deployments, and they are intended to help step up surveillance around the Senkaku islands, a source of heated debate between Japan and China which both claim the remote territories, Reuters reported.
