The guidelines reportedly allow Japan to take on a more assertive military role and clarify US support for Japan.
The United States of America and Japan have unveiled their new guidelines on their defence co-operation, BBC reports.
The guidelines reportedly allow Japan to take on a more assertive military role and clarify US support for Japan even as the US Secretary of State John Kerry said US commitment to Japan's defence was "ironclad".
Although Japan's pacifist constitution currently allows only for self-defence, Japanese prime minister Shinzo Abe has called for a re-interpretation of this.
BBC speculates that any such change is likely to seriously alarm Japan's East Asian neighbours.
Speaking on the strategy change, Kerry said:
"The guidelines that we have worked on that have been announced today will enhance Japan's security, deter threats and contribute to regional peace and stability, the United States and Japan stand together in calling for disputes in the region to be resolved peacefully."
Kerry also renewed the US security pledge over the islets known as the Senkakus in Japan and the Diaoyus in China, areas which are close to important shipping lanes, offer rich fishing grounds and lie near potential oil and gas reserves, and which China has disputed Japan's territorial claim to.
The new guidelines are expected to reflect Japan's shift in its defence aspirations outlined in a cabinet resolution last July, however any further military muscle for Japan would mean an overhaul of its constitution.
Meanwhile, an opinion poll released Japan's Sankei Shimbun newspaper showed 49.5% of Japanese voters opposed legal changes that would allow the Japanese military to fight abroad.
Abe is currently in the United States for talks and is set to visit the site of the 2013 Boston marathon bombing today Monday before travelling to Washington ahead of talks on Tuesday with President Barack Obama.