A women's advocate says Tonga needs to change its laws to be consistent with the Convention on the Rights of the Child.
'Ofa Guttenbeil Likiliki is the director of the Women and Children Crisis Centre.
Her call comes after another NGO, the Talitha Project, launched an initiative seeking to repeal a law that allows children between the ages of 15 and 17 to get married if they have parental consent.
Ms Guttenbeil Likiliki said the government ratified the UN Convention on the Rights of the Child in 1995 and there are still legal inconsistencies.
"You can't vote until you are 21 but compulsory education is until you are 18," she said.
"You can register to be a soldier in the defence services at 16. You can marry at 15 with parental consent and you can be charged for a criminal offence at seven.
"So currently there are huge discrepancies throughout our laws in terms of what actually legally defines a child," Ms Guttenbeil Likiliki said.
Photo: RNZI / Koro Vaka'uta
Fight for CEDAW ratification still not over in Tonga
Ms Guttenbeil Likiliki also said work was continuing on education around Tonga's adoption of the convention on the elimination of discrimination against women.
In 2015 the government stepped back from ratifying CEDAW, after opponents said it would open the way for same-sex marriage and abortion.
The Women and Children Crisis Centre hasn't given up on pushing for ratification.
Ms Guttenbeil Likiliki said CEDAW has been shelved until at least after the 2018 election.
She said in the meantime the centre was holding male advocacy workshops.
She said the last one included 35 men from churches, government, NGOs, businesses and youth groups.
"We brought them together and we took them through CEDAW, every single article, and we unpacked it and we got them to see.
At the end of the five days we had men crying in the room and admitting that they had no idea that CEDAW was actually beneficial for their daughters, for their sisters and this whole misconception around CEDAW being the legislation of same-sex marriage was thrown out the window," Ms Guttenbeil Likiliki said.
She said they would continue to raise awareness so that the public were more informed.