Tokyo - The United States and Japan agreed on Thursday to modernise their defence alliance for the first time in 16 years to address growing concerns about North Korea's nuclear programme, global terrorism, cyber intrusions and other 21st century threats.
The move to modernise the US-Japanese defence alliance follows President Barack Obama's decision to strategically rebalance US forces to the Asia-Pacific region following a dozen years of war in Iraq and Afghanistan.
Washington's desire for Japan to take a greater role in its defence dovetails with the rise of nationalist Prime Minister Shinzo Abe, who has taken a more assertive approach toward such security issues as a territorial dispute with China and the threat from nearby North Korea.
"Our goal is a more balanced and effective alliance," US Defence Secretary Chuck Hagel told a news conference after the first "2+2" meeting to be held in Tokyo.
He was joined by Secretary of State John Kerry, Japanese Foreign Minister Fumio Kishida and Defence Minister Itsunori Onodera.
The two countries pledged in a 10-page statement to rewrite their guidelines for security co-operation, begin rotational deployments of US Global Hawk reconnaissance drones to Japan and work to address challenges in cyberspace.
The ministers agreed to locate a new X-band US missile-defence radar system at Kyogamisaki air base in Kyoto prefecture in western Japan and formalised a decision to relocate 5 000 US Marines from Japan's southernmost island of Okinawa to the US Pacific territory of Guam.
North Korea's nuclear and ballistic missile programmes have become an increasing threat for US allies in the region. Pyongyang conducted a successful ballistic missile launch in December and a third nuclear test this year, but experts say it will probably need more tests before it can develop a nuclear missile.
The pariah state has also threatened a nuclear attack on the United States.
The decision to bolster anti-missile radar coverage in Japan and move Marines to Guam had been announced earlier, but the joint statement fixed the location of the new missile tracking system for the first time and specified Japan's share of the cost of the move to Guam and the Northern Mariana Islands.
Tokyo agreed to contribute up to $3.1bn to help move the Marines to Guam from Okinawa, where their presence has often been a source of friction with the local government and population. The move is expected to cost some $8.6bn.
US Defence and State Department officials say the location of the new anti-missile radar, which is expected to be installed with a year or so, will help improve tracking coverage of rockets launched toward both Japan and the United States.
The US-Japanese agreement also calls for additional efforts to realign US forces in Japan and hand back land to local communities to ensure the political sustainability of the US defence presence in the country.
The ministers also agreed to rewrite the guidelines for US-Japanese Defence Co-operation for the first time since 1997.
The guidelines will be updated to bolster the allies' ability to respond to an armed attack on Japan, expand co-operation on areas such as counter-terrorism and promoting deeper security co-operation between the two partners, the joint agreement said.
The meeting comes as concerns are growing that Japan cannot protect itself from malicious internet hackers.
"Cyber attacks are getting more and more sophisticated, and sometimes we cannot defend against them using the systems we currently have in place," Kazunori Kimura, the Defence Ministry's director of cyber-defence planning, told Reuters TV.