Germany warns that blocking sites does not go far enough.
Germany has called for stronger action to combat images of child sex abuse online, saying material should be deleted rather than blocked.
Justice minister Sabine Leutheusser-Schnarrenberger said Germany "rejected" the idea of stopping people getting access to images by blocking.
Her comments came after the unveiling of European Commission plans to block child sex abuse sites outside Europe.
The blocking plan is part of proposed new laws on child exploitation.
"Blocking," said Ms Leutheusser-Schnarrenberger, "is not an effective weapon in the fight against child pornography and also leads to a loss of trust among internet users."
"I expect a broad debate ... in which I will push the position 'delete, not block'," said the minister during an interview with the Hamburger Abendblatt regional daily newspaper.
Blocking vs deleting
A spokeswoman for the UK Internet Watch Foundation (IWF) said both blocking and deleting had their merits.
"We are clear about what blocking can do," she said. "It can stop inadvertent access."
The IWF is the UK's "notice and take down" agency. When notified about illegal content it can remove it if it is hosted in Britain.
The IWF has reciprocal agreements with similar agencies in 35 other nations which try to get material removed rather than blocked.
But, she added, blocking is a good first step because of the efforts those peddling images of child abuse make to stop the material being removed.
"Commercial content moves around a lot," she said. "A mixture of blocking and removal is a good tactic because it's so dynamic."
Typically, she said, images of child sex abuse are hosted in regions such as the North America and Europe, where net infrastructure is at its most mature.
This is because, she said, this gives those selling images of abuse plenty of places to which they can move the content.