Japan's Constitution is an example for the world — despite changes that have cleared the way for its troops to fight overseas for the first time since the war — the head of a group tipped as a Nobel Peace Prize contender said.

Naomi Takasu, 38, heads a group that seeks to uphold and preserve Article 9, under which the Japanese people "forever renounce war as a sovereign right . . . and the threat or use of force as a means of settling international disputes".

Last month, the Diet voted into law a major security policy reform that could allow Self-Defense Forces troops to fight overseas for the first time since 1945 — a key part of Prime Minister Shinzo Abe's push to loosen the charter's pacifist constraints.