OTTAWA -- United Nations officials say they're concerned vulnerable Canadian children may be falling through the cracks of a fractious federal system that lacks accountability and a clear strategy.

In hearings in Geneva to examine Canada's adherence to the Convention on the Rights of the Child, Ottawa was repeatedly taken to task for incoherence about how federal and provincial programs actually help kids.

The UN's committee on the rights of the child said Canada needs to "raise the bar" in how it protects the rights of children, especially when it comes to aboriginal, disabled and immigrant kids.

The committee also slapped Canada's wrist for allowing corporal punishment, for growing income inequality, and for not yet having brought Omar Khadr back to Canada.

Exports of asbestos, slow action on climate change, and weak controls over the behaviour of Canadian corporations overseas were also raised as concerns.

But committee members said Canada's biggest challenge is to bring together the disparate parts of its political system to implement the convention throughout Canada and improve conditions for vulnerable kids.

"There is a lack of the analysis as to how and how much children's rights have been achieved in the state and how progress has been made," said Marta Mauras Perez, the vice-chair of the committee.

"What we're telling you is really to raise the bar and to rise to the challenge, because Canada is one of the top five economies in the world."

The child rights convention is a binding international treaty that Canada ratified in 1991. Signatories are obliged to defend their child rights' records and explain progress at regular intervals before a UN committee.

Wednesday was Canada's first appearance in 10 years. But committee members complained repeatedly that they could not tell from Ottawa's filings whether progress had been made over that time.

The federal government tabled 127 pages of responses to their questions just two weeks before the hearings, the committee members noted. And while the documents were full of facts, figures and links to websites, they did not show systematically whether any of the provincial or federal initiatives were improving the lives of Canadian children.

"Unfortunately it does not meet the requirements" of the committee, said Mauras Perez.

Indeed, many of the committee's complaints echoed their conclusions from a decade ago: that poverty among aboriginal, black and immigrant children as well as disabled children is significant and growing.

They said they are concerned that many vulnerable groups are overrepresented in detention centres, the health-care system and foster care. But Canada seems to have no way to ensure things don't get worse, or to know whether its programs are tackling the problems efficiently.

The UN, as well as several child rights' organizations in Canada, want to see a national co-ordinator or a national children's advocate who would bring provincial and federal decision-makers together, ensure the Convention on the Rights of the Child is taken into account at every level, and make sure there are high standards across the country.

"We have to ensure there is no disparity and that children throughout the county have the same rights, and that they are not put on unequal footing in any way," said one committee member.

"It is a concern of this body and of others to find ways of offsetting the problems posed by decentralization. There must be a shouldering of co-ordination of certain practices to ensure there is compliance."

In a statement late Wednesday, federal Health Minister Leona Aglukkaq said Canada should be proud of how it takes care of its children.

"Our government has introduced tax breaks to encourage parents to involve their children in sports and the arts, taking action against childhood obesity, and improving education for aboriginal children. As a parent myself I know that Canadians can be proud of this record," she said.

Many provinces, but not all, have children's advocates, said Mary Ellen Turpel-Lafond, president of the Canadian Council of Child and Youth Advocates.

And provincial advocates don't have jurisdiction to wade into federal issues such as refugees and immigration, aboriginal affairs, and the Criminal Code, she said.

"The point is, we have grotesquely unequal outcomes" for certain groups of children, she added.

Federal officials in Geneva explained that they work through an interdepartmental committee on human rights that breaks down issues into various sectors and then engages with provincial and territorial governments to ensure no one falls through the cracks.

"All levels of government in Canada take seriously their obligations under the Convention and its optional protocols, and are committed to protecting and promoting children's rights in an effective, co-operative and meaningful way," Judith Bosse, assistant deputy minister at the Public Health Agency of Canada, told the committee.

In written answers to the committee, Canadian officials also express concern that vulnerable groups are over-represented.

Citing recent research, the Canadian response says First Nations children are 4.2 times more likely to be investigated by child-welfare officials than non-aboriginal children.

That's driven by neglect linked to poverty, substance abuse, social isolation and domestic violence.

To counter the over-representation, Ottawa has increased funding for First Nations child welfare and is in the midst of reorienting its approach toward prevention.