(Adds details on contents of report)
By Linda Sieg and Kiyoshi Takenaka
TOKYO, May 15 (Reuters) - Advisers to Japanese Prime Minister Shinzo Abe called on Thursday for a landmark change in security policy, urging the government to lift a ban that has kept Japan from fighting abroad since its defeat in World War Two.
Citing an increasingly tough security environment, the private advisers called in a report for a change to a long-standing interpretation of the post-war, pacifist constitution that says Japan has the right to defend itself with the minimum force necessary, but that combat abroad exceeds that limit.
"We have reached a situation in which we cannot sufficiently maintain our country's peace and security or realise peace and prosperity of the region and international society under the current interpretation of the constitution," the report by Abe's handpicked advisers said.
A lifting of the ban on "collective self-defence" would be welcome to Japan's ally the United States, but would draw criticism from China, ties with which have been damaged by a territorial row and the legacy of Japan's past aggression.
Abe - who is set to comment on the report at a news conference later in the day - has made clear his desire to loosen the limits of the U.S.-drafted charter.
But doubts remain about how far and how quickly he can go. His Liberal Democratic Party's (LDP) junior partner, the New Komeito, is wary, voters are divided and the LDP's deputy leader is worried about the impact on local polls this year and next.
Previous governments have said Japan has the right of collective self-defence under international law, but that the constitution's pacifist Article 9 prohibited taking such action.
Abe's advisers argue, however, that Japan's security environment, including an increasingly assertive China and volatile North Korea, requires a more flexible approach.
Abe would like to embody the change in a cabinet resolution followed by revisions to relevant laws. A wholesale lifting of the ban soon appears unlikely, although critics say even small changes would open the door to more drastic moves later.
The government is expected to select some concrete scenarios from those cited in the advisers' report and Abe will instruct the ruling parties to start discussing options for change.
Examples in the report include protecting a U.S. warship under attack in waters near Japan; mine-sweeping in sea-lanes in a conflict zone; and intercepting a ballistic missile headed for America.
The advisers said there were no constitutional constraints on Japan's participation in U.N.-led collective security operations, in which nations join to repel an aggressor against one state, but political sources have said the government was unlikely to push for that even more controversial change.
The report also recommends legal changes to allow action in other cases where the military has been constrained by legal concerns, such as rescuing Japanese overseas, using weapons in U.N. peace-keeping operations and dispatching troops to low-intensity conflicts that fall short of a full-scale attack on Japan - so-called "grey zone" incidents. (Editing by Nick Macfie)