Japan's ability to logistically support the U.S. when it retaliates against those behind Tuesday's attacks in the United States depends on how a law on emergencies in "areas surrounding Japan" will be interpreted, said Deputy Chief Cabinet Secretary Shinzo Abe on Sunday.

The government must decide if U.S. strikes can be defined as emergency situations in areas surrounding Japan, Abe said on a morning television program.

"The government position is that 'periphery' in the law is not a geographical concept. But it is assumed that (Japan) will not go to the other side of the globe (to support military action), so we must discuss (whether the expected U.S. retaliatory actions are considered as an emergency situation in Japan's peripheral areas)," he said. "If allowed, basically we will be able to transport (supplies) to non-battle fields, though we cannot provide ammunition," Abe said.