The new deployments agreed to in the first "2+2" meetings held on Japanese soil between the two allies "preserves and promotes a peaceful, prosperous and secure Asia-Pacific region" according to a joint statement released Thursday.
Former Pentagon chief Leon Panetta and Japanese Defense Minister Satoshi Morimoto agreed to begin Global Hawk surveillance flights from Japan last August.
The move was an attempt by the Pentagon to quell growing territorial disputes and regional tensions between China, Tokyo and other American allies in the Pacific.
It also helped advance the Obama administration's efforts to shift U.S. military power from the Mideast into the Asia-Pacific region.
The new regional security pact reached between Japan and the United States reflects the "rising security threats in the region and the increasingly global nature of those threats," Hagel said in a press conference Thursday.
The regional security pact has been in place since 1951, forged in the aftermath of World War II.
The last time American and Japanese officials updated the security pact was in 1997.
But recent developments, from China's increased military presence to North Korea's nuclear ambitions, "urge a re-examination of the agreement governing each nation's roles and responsibilities in defense and contingency operations," Hagel said.
But keeping those tensions — particularly from Beijing — from boiling over into open conflict in the Pacific was a top point of discussion during the U.S.-Japan defense summit.
While Hagel and Kerry reiterated Washington's hands-off stance on regional disputes in the Pacific and elsewhere, the Pentagon chief "strongly opposed" any effort to undermine Japan's sovereignty in the region.
"We strongly oppose any unilateral or coercive action that seeks to undermine Japan's administrative control," he said during Thursday's press conference.
"We will continue to consult especially closely on this issue" and others affecting the U.S.-Japan alliance.
However Hagel or Kerry made no mention of granting first-strike capability to Japan's armed forces.
Japanese military forces are regulated to a self-defense force under the terms of the security pact, preventing Tokyo from launching offensive military operations.
But as potential regional threats from China and North Korea threaten Japan's borders, U.S. officials are ready to consider lifting that ban.
"That is a discussion we have yet to have" with Tokyo, a defense official said on including preemptive strike authority for Japan into the agreement prior to Thursday's meeting.