"By making explicit the status of the SDF in the Constitution during our generation's lifetime, we should leave no room for contending that the SDF may be unconstitutional," the prime minister said.

Japan's current Constitution is best known for its Article 9, in which Japan renounces its right to wage war and promises that "land, sea, and air forces, as well as other war potential, will never be maintained."

The Constitution has never been revised since it went into effect on May 3, 1947.

According to Japanese law, amending the Constitution requires two-thirds approval in both chambers of the bicameral national Diet as well as approval from the majority of the people in a national referendum.

Revising the Constitution has long been a goal of Abe and the ruling Liberal Democratic Party (LDP). The LDP has been advocating constitutional revision as part of its platform since the party was founded in the 1950s, including changing the war-renouncing Article 9.

Abe's ruling LDP and other forces in favor of revising the Constitution won a two-thirds majority in last year's upper house election, bringing the prime minister's goal of constitutional revision closer to fruition.

Public opinions about amending the Constitution, however, remain differed. A recent poll by Japan's Kyodo News showed that 51 percent of the respondents were against any constitutional amendments, while 45 percent were in favor.