UN Secretary-General Kofi Annan, in a new report on child soldiers on Wednesday, said the UN Security Council should hit the individuals responsible with measures such as travel limits, arms embargoes or restrictions on their finances.
Certain abuses should be given priority attention, including killing or maiming children, recruiting or using them as soldiers, attacking schools or hospitals, rape and other sexual violence, abduction of children and cutting them off from humanitarian assistance, Annan said.
The 15-nation Security Council has scheduled a debate on the report for 23 February.
Olara Otunnu, Annan's special envoy for children in armed conflict, said the report marked a milestone for children in combat zones as it signalled the UN was finally getting serious about ensuring their protection.
The issue has been on the council agenda since 1998, but "atrocities against children and impunity for violators continue largely unabated on the ground", Otunnu said.
There are about 300,000 child soldiers around the world today, compared to 380,000 a year and a half ago, he estimated.
Otunnu's office was created as a result of a landmark 1996 report by Graca Machel of Mozambique, now the wife of former South African president Nelson Mandela, who detailed the recruitment and exploitation of children in war zones.
The UN estimates there are
300,000 child soldiers worldwide
The new report says 42 armed groups in 11 nations should be punished for recruiting or using children in war.
The 11 nations are Burundi, Democratic Republic of Congo, Ivory Coast, Somalia, Sudan, Uganda, Myanmar, Nepal, Philippines, Sri Lanka and Colombia.
Nearly all of the 42 armed groups are rebel groups, but government forces from Congo, Myanmar and Uganda also appear on the list.
Dropped this year from previous lists were groups from Angola, Liberia, Sierra Leone, Sri Lanka and southern Sudan - where children are no longer in immediate danger, Otunnu said.
Also missing were paramilitary groups in Northern Ireland and Chechen separatists in Russia, removed from an earlier report after Moscow and London objected to the term "armed conflict" to describe what was going on in their territories.
Also cited in the UN report for the first time are UN peacekeeping forces, after a series of UN investigations found sexual exploitation or abuse against women and children by 20 military personnel in Congo, Otunnu said.