New Komeito leader Takenori Kanzaki suggested Sunday he would support a constitutional amendment that would define the Self-Defense Forces.
"The SDF are thought of overseas as the military, and we could stipulate them in the Constitution," Kanzaki said on a TV Asahi program.
The second clause of the war-renouncing Article 9 says Japan will never maintain land, sea and air forces.
Kanzaki, whose party forms the ruling bloc with the Liberal Democratic Party, also expressed approval for sending the SDF to participate in multinational forces based on U.N. Security Council resolutions as long as they are do not engage in combat.
He said the SDF personnel currently deployed in Iraq on a humanitarian mission could be withdrawn if terror acts become frequent.
"The principle is not to succumb to terror, but there are times when decisions must be made (to withdraw) with overall factors taken into account," he said.
On Prime Minister Junichiro Koizumi's visits to Yasukuni Shrine, which have damaged diplomatic relations with China, Kanzaki suggested that a new facility to honor Japan's war dead should be built.
Yasukuni honors World War II Class-A war criminals among the nation's war dead.