In a bid to heighten antiterrorism preparedness following the devastating attacks in the United States, the ruling coalition agreed Tuesday to enable the Self-Defense Forces to guard public facilities, including U.S. military installations in Japan.

The secretaries general of the three ruling parties agreed to develop a bill to revise the current SDF law to facilitate the change.

The bill is to be submitted during the upcoming Diet session opening Sept. 27, they said.

The current law allows SDF personnel to guard public facilities only after an incident has occurred and the prime minister authorizes their emergency dispatch.

The new law, if enacted, would enable the SDF to join police in guarding such facilities as the Diet, the Prime Minister's Official Residence and nuclear plants.

It would also allow SDF soldiers to fire back if U.S. weapons depots are under attack, said representatives from the Liberal Democratic Party, New Komeito and New Conservative Party.

As for Japan's support for possible U.S. retaliatory action against "those who harbor" terrorists, the ruling parties stopped short of agreeing on drawing up new legislation to allow the SDF to offer logistic support for the U.S.

"We still have to see how the U.S. action will turn out," said the LDP's Nobutaka Machimura, who briefed reporters. "It is too early for us to make a judgment (on whether to create a new law)."

New Komeito seems to remain wary of the planned legislation, which could expand Japan's military role. New Komeito Secretary General Tetsuzo Fuyushiba told reporters after the tripartite meeting that the planned legislation must be enacted only for a specified period of time and should never allow the SDF to transport weapons and ammunition as part of logistic support for U.S. military operations.