TOKYO (AFP) -- Shinzo Abe, the front-runner to become Japan's next prime minister, called Tuesday for the next leader to revise the pacifist constitution imposed after World War II.

"The next leader will have to have the leadership to include a new constitution on his political agenda," Abe, the chief cabinet secretary, said in a speech in Yokohama near Tokyo.

"Drafting a new constitution would open up a new era. We really need this spirit to bring us into a new era," said the 51-year-old conservative.

Abe plans to unveil his platform on September 1 ahead of the September 20 vote of the ruling Liberal Democratic Party that decides on the successor to retiring Prime Minister Junichiro Koizumi.

Abe is expected to pledge to revise the constitution to state clearly that Japan has a military for self-defense, Japanese media have reported.

Japan calls its military the "Self-Defense Forces" because the constitution renounces the right to use force or even to threaten to use force to settle international disputes. The ruling party has proposed revising the constitution to state openly that Japan has a military which can be used for self-defense and can take part in international operations to secure "peace and security."

Most Japanese support the revision, according to opinion polls, but such moves are certain to raise criticism in neighboring countries which suffered from Japan's militarist past.

Koizumi has infuriated China and South Korea by going each year to a shrine honoring war dead and war criminals. He last visited on August 15, the emotionally charged anniversary of Japan's World War II surrender.

Amending the constitution requires a two-thirds majority in Parliament and approval in a nationwide referendum, in which pacifist groups are certain to campaign hard.