TOKYO A visit to Japan by U.S. Defense Secretary Robert Gates will put the focus on security issues between the two allies.
Japanese Prime Minister Yukio Hatoyama, who won a landslide election victory in August, has vowed to steer a more independent diplomatic course from Washington. That has sparked concern among investors about possible friction in the relationship.
Following are questions and answers on some of the issues:
WHAT WILL HAPPEN TO U.S. FORCES IN JAPAN?
Japan, whose own forces are restricted by its pacifist constitution, hosts about 47,000 U.S. military personnel, a source of irritation for communities near military bases, with many complaints about crime, noise, pollution and accidents.
The ruling Democratic Party's election manifesto promised to rethink a planned redeployment of U.S. troops and propose amendments to the agreement under which U.S. troops operate in Japan.
Washington and Tokyo have agreed to ease the burden of U.S. bases on the southern island of Okinawa by moving a 4,000-strong U.S. Marine Corps air base from the center of a town to a less populated area in the north of the island.
The deal means 8,000 Marines will be moved from Okinawa, partly at Japan's expense, to the U.S. territory of Guam.
Washington is keen to press ahead with the project, which is supposed to be completed by 2014, partly because the issue has dragged on since an initial agreement in 1996.
But many residents of Okinawa, which suffered one of the bloodiest battles of World War Two and remained under U.S. control until 1972, are dissatisfied with the plan for environmental and other reasons.
Hatoyama has said the Marine base at Futenma should be moved off Okinawa but has not proposed an alternative location.
The party's proposed changes to the Status of Forces Agreement would include a requirement that U.S. forces make good any damage to the environment caused by their activities, a Japanese newspaper has said.
Several cases of contamination have been discovered at sites returned to Japan by the U.S. military.
HOW FAR WILL JAPAN BACK U.S. MILITARY ACTIVITIES?
Hatoyama said he will not renew the mandate for Japanese ships on a refueling mission in the Indian Ocean in support of U.S.-led operations in Afghanistan, which expires in January.
U.S. officials say the decision is up to Japan, but that they would welcome an alternative contribution to Afghan security.
Officials including Foreign Minister Katsuya Okada have hinted that Japan's future contributions would be civilian rather than military. But Defense Minister Toshimi Kitazawa said last week he was concerned that civilian activities alone might not be a suitable alternative.
WHAT LINE WILL THE NEW GOVT TAKE ON NUCLEAR WEAPONS?
Japan has long been ambivalent about nuclear arms.
Many Japanese use the fact that Japan is the only country to have suffered nuclear attacks as a platform to campaign for the abolition of nuclear weapons.
Hatoyama backs U.S. President Barack Obama's calls for a world free of nuclear arms and has promised to uphold Japan's three "non-nuclear principles" banning the making, possession or introduction into the country of nuclear arms.
He has also said he will seek a U.S. pledge not to bring nuclear-armed vessels into Japanese ports.
But Japan benefits from a nuclear "umbrella" provided by Washington, something many see as important given China's growing military might and North Korea's nuclear program.
HOW WILL JAPAN'S ASIA STRATEGY CHANGE?
Hatoyama advocates a new East Asian Community modeled after the European Union, although he concedes it would take more than 10 years to set up a unified regional currency.
He wants to deepen ties with China and has said he will stay away from Yasukuni, a war shrine in Tokyo seen by many in Asia as a symbol of Japan's military aggression in the early 20th century.
(Editing by Dean Yates)