By Susannah Price
BBC UN correspondent
The UN Security Council has unanimously approved a resolution aimed at protecting children in armed conflict.
Child soldier recruitment is one of the abuses the UN wants to curb
The council agreed to monitor more than 50 governments and rebel groups accused of violating children's rights and punish those who did not stop.
Abuses include killing or maiming children, using child soldiers and sexual violence against children.
In February a list was made of states and rebel groups involved in 11 conflicts who did not protect children.
A UN report published earlier this year named those who recruited children for fighting, which included the Tamil Tigers in Sri Lanka and groups in Burundi, Sudan, the Ivory Coast, the Democratic Republic of Congo and Somalia.
Some groups such as the rebels in Nepal, the Lord's Resistance Army in Uganda, and the Janjaweed militia in Darfur Sudan, were also found to have killed, maimed and abducted children.
The Security Council ordered all those named to implement concrete action plans for ending violations against children and established groups to monitor the outcome.
The UN special representative for children in armed conflict, Olara Otunnu, called it a turning-point.
"I'm very hopeful actually that a good number of parties will respond to this," he said.
"Already, even before the Security Council resolution, we have been in touch with a number of them and they are very eager to be engaged and to have their names off this list of shame."
The council agreed to consider targeted measures if the governments or rebel groups did not make enough progress.
These could include travel restrictions, arms embargos, a ban on military assistance or financial restrictions.
Mr Otunnu said most of the groups were sensitive to outside pressure.
According to the UN, two million children have been killed in armed conflicts in the past decade and there are currently a quarter of a million child soldiers involved in various conflicts.