A working group of nine ministries and agencies has reached agreement that Internet access to child pornography sites should be blocked as soon as they are discovered, rather than waiting for site operators to comply with requests to take them down, officials said Thursday.

The accord came after the communications ministry, which argued that the government should be cautious about taking the step, was persuaded by the National Police Agency and other ministries that protecting children should come first, because online images can be easily copied and spread, exacerbating the potential damage to victimized children.

Fearing that forcibly cutting off access to certain Web sites could infringe on the constitutionally guaranteed secrecy of communications and the freedom of expression, the Internal Affairs and Communications Ministry had said access should be blocked only when deleting the harmful sites is difficult, the officials said.

The Cabinet will aim to adopt a set of measures against child pornography, including the blocking of Internet sites, in June so they can be implemented by next spring, they said.

Under the plan, the NPA and the Internet Hotline Center, an organization working in collaboration with the NPA, will be in charge of detecting child pornography sites.

As soon as such sites are discovered, Net service providers will promptly block access to them, police will investigate, and the center will request their deletion by site operators.

Child porn sites with servers located outside Japan will be also subject to the step.

NPA chief Takaharu Ando praised the new step.

"This is a great leap forward," Ando said. "Police will cooperate with relevant bodies as we try to formulate truly effective measures to block targeted Web sites."

Among the Group of Eight nations, only Japan and Russia do not prohibit possession of child pornography.