The United States Tuesday welcomed a historic shift by Japan to expand the role of its military by reinterpreting the terms of the nation's US-imposed constitution.
"We have followed with interest the extensive discussion within Japan on the issue of exercising its right under the UN Charter to collective self-defense," State Department deputy spokeswoman Marie Harf said.
"We welcome the government of Japan's new policy regarding collective self-defense and related security matters."
After months of political horse-trading and browbeating of opponents, Japanese Prime Minister Shinzo Abe said his cabinet had formally endorsed a reinterpretation of rules that have banned the use of armed force except in very narrowly-defined circumstances.
Under the new definition, Japanese troops will now be able to come to the aid of allies -- primarily the United States -- if they come under attack from a common enemy, even if Japan is not the object of the attack.
The dramatic shift comes amid soaring regional tensions with China centered on disputed islands in both the South China and East China seas.
Abe had originally planned to change Article 9 of the US-imposed constitution, which was adopted after World War II and renounces "the threat or use of force as means of settling international disputes."
But unable to muster the two-thirds majority he needed in both houses and unlikely to get an endorsemen from the public in the required referendum, he changed tack, opting to reinterpret the rules.
Harf said the US-Japan alliance was "one of our most important... security partnerships."
"We value efforts by Japan to strengthen that security cooperation and also value Japan's efforts to maintain openness and transparency throughout this decision-making process that's led up to this new policy."